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"noble savages as jealous of intrusion as in 1873, and cannot their antipathy to strange faces and cloth coats be overcome, either by law, stratagem, or civility? Perhaps some brother of the net and pin can throw light on the present condition of this queer "preserve."-W. H. G.

FOSSILS NEAR WATFORD.-In the very useful "Saturday Half-Holiday Guide" for 1873,mention is made of a chalk-pit in Berry Wood, near Aldenham, one mile and a half from Watford, abounding in well-preserved fossils of various kinds. May I ask if this pit is still available to the geological excursionist ?-W. H. G.

WHITE BEES, &c.-A subscriber would be glad if any of your correspondents can inform her what are the "White Bees," which bees occasionally turn out of their hives, and why they put them out. The only mention she finds made of them in Pettigrew's 'Handy-book of Bees" is, that the bees turn them out when " on the border-land of starvation." She has only begun to keep bees this year, and during the wet weather had four white bees put out, and later, two, very small ones. She has fed the bees constantly during wet weather, and on rainy days. Also, can any contributor to the SCIENCE-GOSSIP explain the formation of stones called Mocoes," found at Aberystwyth, and probably other places on the Welsh coast? When cut and polished, they are like pieces of sea-weed floating in the stone, which is transparent, as if water and weed had both been suddenly changed to stone. The weed in many cases is very perfect, and there are several different kinds. Are they petrifactions, or fossils? And are they of modern or ancient formation? I have been unable to find any description or account of them in the books I have been able to refer to.-E. 4. K.

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POPLAR HAWK CATERPILLARS.-I have reared considerable number of these caterpillars from the egg upwards, but have never experienced what your correspondent states in the September number of this magazine. When first hatched they were very delicate indeed, generally half their number dying; but after they once got over their first moult they were as voracious and healthy as could be wished. The young caterpillars should be kept in a small box, until they are large enough to be removed into the breeding-cage, as this prevents their wandering too far away from their food, which is an important point when they are very young. Many people seem to think that young caterpillars require young and tender leaves; this is true enough, and holds well with many species, but certainly not those feeding on poplar, as the young leaves and shoots are always more or less covered with a gummy substance, which seems to answer the same purpose as birdlime, for no sooner do the young caterpillars attempt to walk over them than they stick fast, and soon die. I have lost numbers in this way. I need hardly say that they should be handled as little as possible, and not kept in a very warm room.-C. P. Hall, Woolwich.

OXEN AND MUSIC.-I have often noticed the power music has over oxen. The other day we had a brass band playing in our garden. In a field adjoining were four Scotch oxen; when the band struck up they were at the far end of this, a nineacre field, quite out of sight, the field being very uneven-they set off full trot to the garden wall, put their necks over, and remained so till the tune

was finished, when they went back to graze; but as soon as it struck up again, they put their heads over the wall again. This went on till the band left, after which they ate little all day, and were continually lowing.-L. W.

FROGS AND GOLDFISH.-A friend of mine had a small pond, in which he kept goldfish. These began to die very fast. He could not account for it at all: till at last one night he went very quietly up to the pond, and to his surprise saw four frogs, each swimming on the back of a goldfish, holding on by their webbed feet; the fish were swimming with their backs out of the water, and seemed as if they could not descend with their riders. In time all the fish died. Can it be accounted for by the frogs on them ?-L. W.

SPARROWS AND PEAS.-Sparrows (Passer domesticus and P. montanus) do an unknown amount of harm in the kitchen garden, by eating the young shoots of beet, peas, and beans. My peas were kept back a fortnight, and the beet is quite ruined this year. I was told soot would stop them; so I got some, and after I had sown my peas, I covered them over with it, and they have not been touched. What can there be in soot that keeps them off ?L. W.

DEATH OF ROBINS.-There is a saying in North Lincolnshire that all the two-year-old robins (Erythaca rubecula) kill all the three-year-old birds in autumn. Is there any truth in this or not? I have watched them for some years, and certainly they are a quarrelsome set, but I have not found that they kill each other. There is also a belief that it is unlucky to take robins; so, when all other. birds' nests are taken, it is watched with reverent care.-L. W.

CRABS OUT OF WATER.-On Tuesday, September 7, the gardener, in procuring a can of seawater for the aquarium, captured a few small shore crabs, known here as "king crabs" (Carcinus mœnas), one or two of which escaped from the can after it was brought into the garden. On the 9th one of the crabs was found walking about on the stone steps, apparently none the worse for forty-eight hours' absence from the ocean. A trifling shower on the morning of the 8th might have supplied it with a little moisture which would probably be beneficial, though immersion in fresh water is fatal to marine crustacea.-G. Guyon.

FISH-CANS." A self-air-acting fish-can" is referred to by A. G. R. Sclater, in his notes on "Goldfish Breeding," in September SCIENCE-GOSSIP. What sort of can is this,-can he describe the arrangement ?-G. S.

COMMUNICATIONS RECEIVED UP TO 9TH ULT. FROM :A. P.-E. T. E.-W. P.-W. K. M.- Dr. R. M. B.-J. E. L.— T. G. P. Y.-G. G.-W. H.-F. K.-E. L.-A. B.-R. C. B.J. C.-T. J. B.—S. A. S.-J. B.-J. F. R.-H. W. L.-C. P. H. -E. A. K.-W. H. G.-J. H. M.-L. W.-C. O. G. N.G. S.-J. A. jun.-Dr. G. B.-S. J. B.-W. H. H.-W. T. B.F. J. A.-E. W. A.-Dr. C. R. A.-B. B.-E. A. B.-W. G. P. -W. J. H.-J. P. W.-W. K. G.-W. H. G.-B. B. W.W. R. J.-E. T. S.-F. E. F.-W. T.-C. D.-W. H. H.W. T. S.-W. E.-F. H. A.-C. H. M.-F. M.-J. C.-W. J. L. -F. E. F.-H. E. W.-P. S. S.-H. G. G.-C. L.-J. G.T. R.-J. G. R. P.-8. A. B.-G. C. D—J. B.-J. R.W. H. C.-H. S. F.-C. D.-F. H. W.-C. D. W.-F. W. M.R. D.-W. A. L.-E. J. L.-D. M.-T. H.-R. H. P.-E. C.T. B. W.-J. I.-C. T. F. N.-W. F.-C. A. O.-E. E-C. A. -G. H. K.-J. R. 8. C.-T. C. O.-W. R. H.-M. P. E.E. M.-E. L.-J. S. H.-E. D. B. M.-W. W.-C. L. J.-W. C. &c. &c.

NOTICES TO CORRESPONDENTS.

TO CORRESPONDENTS AND EXCHANGERS.-As we now publish SCIENCE-GOSSIP at least a week earlier than heretofore, we cannot possibly insert in the following number any communications which reach us later than the 8th of each

month.

FLOWERING RUSH.-The correspondent who wanted this plant in exchange for Sundews, &c., forgot to give his name and address.

W. H. HATCHER.-No specimen of green flower was enclosed in your note. It must have been omitted in sealing. C. W. H.-One of the best Elementary books on Zoology is Prof. Nicholson's, published by Blackwood, at 2s. 6d.

W. L. W. E. (Winchester).-Your plant is Rubus odoratus. THE WANDERER.-You are correct in supposing the species to be insectivorous: it is the Drosera binata, closely allied to the elegant little Sundews of our bogs.

H. F. E. W. (West Meon).-The shrubby plant, with spines without flowers or fruit, is indeterminable. Perhaps you would look out for flowers next season. The common, or local names of plants or trees, are never very reliable, they vary much with locality. We shall at all times be most happy to aid you; you cannot send us too many queries.

C. T. (Bournemouth).-It is not M. altissima, but, as you imagine, the true Melilotus alba.

W. A. LAW.-Your specimen is a Myriapod (Geophilus electricus), well known for leaving a phosphorescent trail on damp hedge-banks, &c. It is not an uncommon insect.

W. FARROW is desirous of obtaining specimens of the Grass of Parnassus. Will some of our readers send a specimen? S. J. BARNES.-You can obtain, mounted and named, British Sea-weeds either separate or as a perfect collection, by applying to 192, Piccadilly.

D. O. N.-One of the handiest books we know on the subject is William Swainson's "Treatise on Taxidermy."

T. J. B.-We would advise you to get "Wild Flowers worth Notice," by Mrs. Lankester, published by R. Hardwicke, 192, Piccadilly.

E. M. GREENFIELD. You can gain what information you require by applying to Van Voorst, the publisher of the books you mention.

E. W. ANDREWS.-The objects enclosed were the eggcapsules of a species of Natica.

EXCHANGES.

Ecos of Golden Plover, Ring Ouzel, Lesser Redpole, Mountain Linnet, Kingfisher, for other good Eggs.-Address, Jas. Ingleby, Eavestone, near Ripon.

WANTED, Parasites, mounted or unmounted; will give other Material unmounted.-F. E. Fletcher, Eastnor House, South Norwood.

Mentha rotundifolia, for any of the following Labiata:945, 948, 949, 954, 956, 958, 965, 966, 971, 985.-Rev. F. H. Arnold, Fishbourne, Chichester.

FOR large Male Antenna of Bombyx Yama-mai, send a stamped directed envelope to W. H. Gomm, Somerton, Taunton.

MOUNTED Tentacle of Drosera rotundifolia, for other well-mounted Slide.-J. B., 224, West George-street, Glasgow. WANTED, Parasites, mounted or unmounted, for other Material unmounted, or Coloured Varnish for ringing.-F. E. Fletcher, Eastnor House, South Norwood.

Malva borealis, for Nos. 1302, 1487, or other rare plants.C. A. Oakeshott, 8, St. Andrew's-square, Hastings.

FOR Sheep Tick, Melophagus ovinus, mounted in balsam, send any good Slide to A. Haward, 1, Shirley Villas, Addiscombe, Croydon.

Rosa Wilsoni et sylvestris (Menai Bridge), for other Roses, &c.-H. S. Fisher, 1, Gladstone-road, Edge- hill, Liverpool.

Ecus of Heren, Grouse, Guillemot, Sandpiper, Sandwich Tern, Black-headed Gull, and Green Woodpecker, for other good specimens.-Alfred Bindon, 22, Argyll-street, London, W.

EGGS of Lesser B. B. Gull, Pratincole, Sandwich Tern, Kentish Plover, and Fieldfare, for other rare Eggs.-C. Dixon, 60, Albert-road, Heeley, near Sheffield.

OFFERED, good specimens of Sphinx Convolvuli for Sphinx Pinastri, or specimens of the Deilephila.-Rev. F. H. Wood, 2, Clarence Villas, Finsbury-park, London.

A FEW Beetles (continental species), mounted and named, offered for odd Nos. of GosSIP, for 1874.-G., 15, Thornhillroad, N.

A FEW specimens of Lepidoptera, Shells, Birds' Eggs, and Minerals.-G. T. F. Napier, Alderley Edge, Cheshire.

FOR well-mounted section of Ivory, send really good Slide (number limited) to J. Green, March.

HAIR of Opossum (unmounted), for any object of interest, also Foreign Shells for others.-F. W. M.. 40, Bengal-street, Bradford.

EGGS of Teal, Heron, Quail, Kestrel, Sparrow-hawk, Carrion Crow, Coot, Stonechat, Lesser Redpole, and others, for good Lepidoptera.-W. Howard Campbell, Ballynagard House, Londonderry. Ireland.

UNMOUNTED Microscopic Material for other, or for Slides. Lists exchanged.-R. H. Philip, 28, Prospect-street, Hull. WANTED to purchase for herbarium, rare European and other Saxifrages.-Address, T. H., Highfield, Sydenhamn-hill, London.

CORRESPONDENTS wanted abroad to exchange British Lepidoptera for those of foreign countries. I would also exchange British Lepidoptera for Birds' Eggs.-W. Watkins, 21, Caves-terrace, Shepherd's-bush, W.

Colchicum in flower, Linaria spuria, and Elatine, Eriocaulon septangulare, Scirpus pauciflorus, for other plants.-G. C. Druce, Northampton.

Helianthemum guttatum (Mill), from Boffin Island, co. Mayo; also Menziesia polifolia (Juss.), from Connemara, for rare British Plants.-Richard M. Barrington, LL.D., Fassaroe, Bray, co. Wicklow.

WANTED, Nos. 149b, 870, 878, 1266, 1604b, 1616b, 1623b, 1634b, c, 1636, 1649, 1653; offered: 158, 235, 236, 237, 239, 253, 304, 305b, 306b, 328, 330, 335, 388, 611, 749, 835b, 887, 923, 1004, 1344, 1345, 1375, 1376, 1466, 1483, 7th edition, London Catalogue.-James Cunnack, Helston, Cornwall.

CUBA, Jamaica, and South Sea Shells, Tropical Seeds, Minerals, Adriatic Seaweeds named, for Micro. Slides.-N., 18, Elgin-road, St. Peter's-park, W.

WANTED, Helix virgata or rufescens (from localities north of Leeds), Pupa secale, Anglica or Muscorum; offered. Clausilia biplicata, Zonites nitidus, Assiminea Grayana.— W. H. Hatcher, Belmont Works, Battersea, London.

WANTED, Slides, well mounted, illustrating Physiology and Anatomy; will give two good Slides for one good Slide showing sweat-ducts and glands plainly. Great many Slides to exchange.-W. Tylar, 165, Well-street, Birmingham.

MAHOGANY, cork-lined, air-tight case, with over 200 specimens of British and Foreign Beetles; also a similar case with a few Orthoptera and Lepidoptera, for Microscopic or other articles.-W. G., Gordon-street, Nairn, N.B.

WANTED two or three dozen each of the larger British Land and Freshwater Snails, H. aspersa, H. pomatia, L. stagnalis, &c., alive. First-class Micro. Slides or Cash.C. L. Jackson, Hesketh, near Southport.

Linnæa glabra offered for Helix lamillata, H. revelata, H. obvoluta, Bulimus montanus, Clausilia Rolphii, C. laminata, C. biplicata, Cyclostoma elegans, &c.-Edward Collier, 6, Short-street, Tib-street, Manchester.

WANTED, Healthy Plants of Flowering Rush (Butomus), Arrowhead (Sagittaria), Water Soldier (Stratiotes). Good Plants of Sundew, Drosera rotundifolia (see Darwin's "Insectivorous Plants") will be given.-Miss E. De B. Meyrick, Downshire Lodge, Blessington, co. Wicklow.

Hyas araneus, Corystes Cussivelaunus, and other Crabs for Lithodes maia, Nephrops Norvegicus, or other northern species. Lists exchanged.-Thos. Russell, 48, Essex-street, Strand, W.C.

SMITH'S best th Objective, with screw adjusting collar, and Kirby & Spence's "Entomology," 4 vols., original edition, with MS. notes, by Mr. Spence, for a good th orth. A little cash given as well, if required.-J. S. Harrison, 48, Lowgate, Hull.

CORNISH PLANTS:-125, 139, 854, 944, 946, 947, 948, 956, 981, 1052, 1389, 1401, 1485, 1486, 1508, 1651, London Catalogue, 7th edition.-Wm. Curnow, Pembroke Cottage, Newlyn Cliff, Penzance.

DUPLICATES of H. velleda, L. complanula, E. jacobœœ, C. dominula, L. chrysorrhœa, L. auriflua, L. dispar, W. sambucata, M. margaritaria, D. aversata, F. piniaria, M. ocellata, &c. &c. Desiderata: Lepidoptera, Birds' Eggs, or Mollusca.W. K. Mann, Granby House, Granby Hill, Clifton, Bristol.

BOOKS, &c. RECEIVED.

"Climate and Time." By James Croll. London: Daldy, Isbister, & Co.

"The Dawn of Life." By Principal Dawson. London: Hodder & Stoughton.

"Introductory Zoology." By Prof. Nicholson, 2nd edition. London: W. Blackwood & Son.

"Zoology for Students." By D. Carter Blake. London: Daldy, Isbister, & Co.

"Report of Botanical Localists' Record Club."

"How to Use the Microscope." By John Phin. New York.

"Monthly Microscopical Journal." October.

Popular Science Review."

"Canadian Entomologist."

"American Naturalist." August.

"Land and Water." October.

"Les Mondes." October.

"Monthly Journal of Education," October.

"Ben Brierley's Journal."

HISTORY OF OUR CULTIVATED VEGETABLES.

No. XIV. THE ARTICHOKE (CYNARA).

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HIS singular, but handsome vegetable, is nearly allied to the carduus, or thistle, and is a native of some of the warmer parts

of the temperate zone; it is also considered to be indigenous to the countries which bound the Mediterranean, as well as the islands which are situated in that sea. It is almost impossible to trace when this vegetable was first used as food, but Dioscorides mentions it more than half a century before the Christian era. Two Greek authors, of an early date, recommended mothers desirous of having male children to partake freely of this vegetable. Both Greeks and Romans appear to have procured this plant from the coast of Africa, about Carthage, and also from Sicily. This vegetable is said by Pliny to have been more esteemed and to have obtained a higher price than any other garden herb. He was ashamed to rank it among the choice plants of the garden, being, in fact, no other than a thistle. He states that the thistles about Carthage and Corduba especially, cost the Romans annually 6,000,000 sesterces, about £30,000 sterling; and concludes by censuring the vanity and prodigality of his countrymen in serving up such things at table as the very asses and other beasts refuse, for fear of pricking their lips. We are also informed by the same author that the commoners of Rome were prohibited by an arbitrary law from eating this vegetable. The Romans used to preserve the artichoke in honey and vinegar, and season it with the root of laserwort (Laserpitium glabrum) and cumin (Cuminum cyminum), by which means they were to No. 132.

be had every day in the year. The juice of the artichoke, pressed out before it blossomed, was used by the ancients to restore the hair of the head, even when it was quite bald. They also ate the root of this plant (as well as that of the thistle) sodden with water, to enable them to drink to excess, as they excited a desire for liquor. Columella notices the same quality in the artichoke, but intimates that it injures the voice,

"Let the prickly artichoke

Be planted, which to Bacchus, when he drinks Is grateful; not to Phoebus, when he sings." Pliny tells us that these thistles are grown in two different ways, from plants set in the autumn, and from seed sown before the Nones of March (7th), in which case they are transplanted before the Ides of November (13th), or, where the site is a cold one, about the time when the west wind prevails. They are sometimes even manured, and, if such is the will of Heaven, grow all the better for it."

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Bechmann, in his "History of Inventions," made very laborious researches to ascertain the positive antiquity of the artichoke, and these discussions are both curious and interesting. We find the first mention of this vegetable, in more modern times, about the fifteenth century, when it was introduced into Italy from the Levant, and considered as a new species of food. In 1466 one of the Strozzi family brought the first artichokes from Florence to Naples. A commentator of Dioscorides, Hermoleus Barbarus, who died in 1494, relates that this vegetable was first seen in the Venice garden in 1473, at which time it was very scarce. It was introduced into France at the beginning of the sixteenth century; and not many years after, during the reign of Henry VIII., was first transplanted into our gardens. In the Privy Purse expenses of this king we find several entries regarding artichokes. Thus,-"Paied to a servant of maister Tresorer in rewarde for bringing Archecokks to the king's grace to Yorke-place, iiijs. iiijd." A treatise, written in the reign of Mary, on the "best settynge

N

and keepynge of artichokes," is still preserved in the Harleian Library, of which it forms the 645th number.

Gerard has left us correct representations of both the French and the Globe varieties, but makes no mention of their country or their introduction; we may therefore conclude that they were become common in 1596. By reason of the great moisture of our climate, and the attention which was paid to its cultivation, the artichoke soon became so much improved in size and flavour that the Italians sent for plants from England, deeming them to be of another kind; but they soon returned to their natural size when restored to that country. In its wild state the plant is said to be taller, more downy and spinous, than it appears in our kitchen-gardens. It is cultivated in almost every part of Europe, but in England it is grown rather as a luxury than a profitable succulent. On account of the great size of its roots, and of its penetrating the soil so deep, it withstands the dry and hot summers about Paris, where they are most extensively cultivated and most abundantly used. Artichokes are a favourite dish at a French breakfast; sometimes they are eaten uncooked in a young state as a salad. The young heads, when about 2 in. in diameter, make excellent pickle. In England they are generally boiled, and the scales of the calyx are then plucked off one by one, the lower part of them dipped in melted butter, and the fleshy substance sucked from the rest. But there is generally so little to be obtained, as almost to justify the observation of a raw country servant, who, having waited at supper when artichokes made one of the dishes, was eager on his return to the kitchen to taste a kind of food he had never seen before, but to his great disappointment, finding little more than a horny substance which equally defied his tongue and his teeth, declared with great naïveté that gentlefolk seemed to him to have strange fancies, for, as far as he could discover, one leaf would do as well to lick up butter as a thousand. It was fortunate for him

a maritime plant, or at least one which thrives best on soils where there is a mixture of saline or alkaline matter. In the time of John Evelyn, 1699, the island of Jersey was famous for its artichokes, on account of the seaweed used in manuring the land; and it is said that in the present day this vegetable is successfully cultivated in the Orkney Islands from the same cause.

Medicinally, the stalks are considered aperient and diuretic; the leaves in their natural state. boiled in white wine whey, are thought beneficial in the case of jaundice; and when cut into pieces and steeped in sherry wine, are an excellent antibilious medicine.

The generic name Cynara is said to be derived from the word cinis, because, according to Columella, the land for artichokes should be manured with ashes; and Gerard says the same thing. Parkinson says it is so called from the colour of its leaves. Heathen mythology informs us that Cynara was a young and beautiful girl who had the misfortune to displease one of the gods, who instantly metamorphosed her into an artichoke. (Ruell, i.

20.) Respecting the origin of the word artichoke, various conjectures have been formed. It has been by some authors derived from the Greek word coccalon, which signifies a fir-cone, with the Arabic al prefixed; this, again, has been denied, and the word drawn from the Arabic name, harraf, or harchiaf.

The artichoke has been introduced into the Pampas of South America, and has spread over a large tract of country in such abundance as to form impenetrable masses when in flower. (Vide Oliver, "Lesson in Elementary Botany.")

HAMPDEN G. GLASSPOOLE.

THE RESTING SPORES OF THE POTATO FUNGUS (continued).

BY WORTHINGTON G. SMITH, F.L.S.

that he did not encounter what is emphatically SINCE this subject has been made public, Mr.

styled, the "choke," from not an ill-founded persuasion that any unlucky wight who should happen to get it into his throat would certainly be choked. This consists of the unopened florets and bristles which stand upon the receptacle of the compound flower, and must be carefully cleared away before the epicure can arrive at the receptacle itself, the bottom, as we call it, or le cul, as it is more elegantly termed by our polished and refined neighbours on the other side of the Channel, which is undeniably the most plentiful as well as the most delicate part of the viand; and in France it is esteemed a branch of good housewifery to preserve this part to the use of the family during the winter. (Rees's "Cyclopædia.")

The artichoke, like the asparagus, is naturally

Carruthers has kindly furnished me with a copy

As

of Dr. Farlow's paper on the Potato Rot, extracted from the "Bulletin of the Bussy Institution," part iv., a paper I had not previously seen. some of Dr. Farlow's practical observations seem to have a direct bearing on some of the points raised by me, I will conclude by extracting one or two sentences:-"The disease is first recognized by brown spots on the leaves" (p. 320). "If we examine any potato-plant affected by the rot, even before any spots have appeared on the leaves, we shall always find these threads in the leaves, stem and, in fact, nearly the whole plant” (p. 322). "The Peronospora is much more easily affected by moisture than the potato-plant itself." "Suppose the temperature to keep equally warm, and the

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atmosphere to become very damp, then the absorbing power of the mycelium is very much increased, while the assimilating power of the leaf-cells is little altered. Thus it happens that a sudden change from dry weather to moist will cause the mycelium to increase so very much beyond the power of the potato-plant to support it, that in the struggle for existence the latter blackens and dies." When the disease has arrived at a certain point, viz. just about the time of the appearance of the spots on the leaves, these mycelial threads make their way into the air" (p. 323).

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I give in conclusion an illustration of the perfectly mature resting spore of Peronospora infestans, as seen imbedded in the substance of the potato-leaf. These resting spores, which carry on the winter life of the fungus, are not restricted to the leaves, for I find them sparingly in both haulm and tuber, although I have at present seen the best specimens in the leaves. The engraving given herewith (fig. 164) shows a transverse section through a black spot of one of the leaves from Chiswick, and the resting spore is seen at A, nestling in amongst the cells of the leaf. An antheridium, B, and two oogonia (c, c), from which such resting spores arise, may be seen in the cut, and the old common form of the fungus will be noticed breaking through a hair on the upper surface of the leaf, which is a very uncommon occurrence. The situation of the resting spores can generally be ascertained on the leaves by noticing the slightly thickened and very dark spots, for the bodies are commonly in these spots. It is, however, an extremely difficult matter either to get them out, or, indeed, to see them when imbedded, for, when mature, they are black-brown in colour, and only a little larger in size than the leafcells. These leaf-cells are also intense brown-black in colour, from contact with the hurtful mycelium, and almost as hard as wood. The best way to see the resting spores is to macerate the leaves for several days in water, and then set them free by crushing the spot between two slips of glass. The presence of the fungus in the leaf makes the cells very thick and woody as well as black, so that in crushing the leaf-cells the resting spore is not uncommonly crushed at the same time. With care, however, they can be got at, when they will be seen, as at D, covered with warts or coarse reticulations, and beautifully regular and perfect in out. line: when young they are of a pure warm sienna colour, and when perfectly mature, brown-black and shining. They are spherical or slightly eggshaped, and measure on an average about onethousandth of an inch in diameter. I consider it worthy of special note that these resting spores are almost exactly the same in size, conformation, and colour with Peronospora arenaria, Berk., an allied species found parasitic on Arenaria trinervis. In looking for these bodies care must be taken not to

confound them with corroded cells, granules of starch injured by the disease, or foreign bodies.

At E is shown a semi-mature resting spore with pollinodium attached, accidentally half washed out of its coating of cellulose by maceration in water.

I may say, as an addendum, that to me there is a marked analogy in size and habit on the one hand between the oogonia and the vesicles which contain the zoospores, and on the other hand between the simple spores and the antheridia. I consider that the oogonia and antheridia are merely the intercellular condition of the vesicles which contain the zoospores and conidia, which latter are the aërial state of the former.

The facts which point in the direction just indicated are these: sometimes there is no differentiation in the contents of the vesicles, but the plasma is discharged in one mass and not in the zoospore condition; the vesicle then resembles the oogonium. At other times the oogonium shows a distinct differentiation in its contents, and matures from one to three resting spores, which to me shows an approach to the condition of the vesicle which usually gives birth to the zoospores.-See also the Gardener's Chronicle, July 17 and 24, from which the above plates have been taken.

Since the above observations were printed, the following facts have been observed by me, and recorded in the Gardener's Chronicle for July 31.

1. Some plants sent to the Royal Horticultural Society by Mr. Dean, on July 21, were covered with the Peronospora far beyond anything I had ever seen before. The haulm, the leaves (on both sides alike), and the berries were covered. Some of these plants, after being placed on a garden bed, and covered with leaves (to keep them moist), were the next day one white mass with the Peronospora.

2. The potato fungus (as commonly seen) bears a far larger number of simple spores than inflated vesicles containing the zoospores or swarm-spores, but in Mr. Dean's plants the fungus produced zoospores almost exclusively, and in the greatest abundance. As the zoospore is a higher development of the plant than the simple spore, this latter observation points to the unusually robust health of the fungus this season.

3. On suspending the infected leaves over a glass of water for from twelve to seventy-two hours, the swarm-spores fell in abundance (either free or in the vesicle) on to the water, and there germinated. No single drop of the water could be taken up for examination without meeting with the germinating spores, the threads radiating over the water in every direction, evidently in quite a congenial element. It brought the following fact to light, which is of importance some of the vesicles which usually discharge the zoospores discharged instead a thick mass of mycelium; and this cord, when it had proceeded a considerable distance over the water, there

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