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I think therefore that M. Girard's conclusion, that only the inner farinaceous portion of the grain should be used for human alimentation, and that it should be the aim of the miller to completely eliminate from his flour all the other parts, is refuted rather than supported by what he tells us concerning the cerealin. On the other hand, the facts concerning the nondigestibility of the bran indicate considerable exaggeration in the claims of some of the whole-meal candidates.

Assuming that the cerealin does act on the starch and gluten as stated, it is a benefactor, and we may do well to retain the outer skin of the wheat for its sake alone, even though the other nitrogenous and mineral constituents may not be assimilable. Besides this, there is the physiological question of the stimulating action of such a husky material on the bowels to be considered. Is it good or evil? Evidently the whole-meal question is not yet settled.

I may add that Dr. Randolph has, in the "Notes from the Physiological Laboratory of the University of Pennsylvania," a paper on the nutritive value of branny foods. He concludes, after a prolonged course of experiments, that the carbohydrates of bran are digested by man in a slight degree only; but as the nutritive salts of wheat are chiefly contained in the bran, those who feed on bread alone should take it brown for the sake of these salts, while those who use other food supplying such salts should select white bread; and that in an ordinary mixed diet the retention of the bran is a false economy, as it quickens peristaltic action and thereby prevents the complete digestion and absorption, not only of the proteids contained in the branny food, but of other food matters mixed with it. To this I think the "bread reformers" may fairly reply, that the peristaltic movement is a part of the machinery of digestion, the promotion of which may be beneficial; it is certainly needed in some cases of sluggish action, and it probably increases the secretion of animal diastase (intestinal juice) in the intestines. On the whole, I am inclined to conclude that whole-meal bread is best for vegetarians, though perhaps not so for those who eat flesh.

The following letter from Dr. Keegan shows that the difference between us is still less than even his first letter indicated::

Mr. Williams, in his reply (p. 200) to my remarks, dwells upon the savagery, brutality, and obtuse moral sense of some of Homer's heroes, and upon the general obscenity saturating (as he avers) much of the old classic literature. Now, the works of Homer are generally known to be a collection of legends relative to a social state far in the depths of human history, and therefore it may be doubted if their perusal is eminently calculated to demoralise persons reared in the light of more advanced and exalted ideas. With regard to the other matter, it may be replied, that a similar sort of immorality pervades, to

some extent, the literature of every people in the world. The works of our own peerless dramatists of the time of Elizabeth and of Charles II. are not utterly free from a blackguardly indecency of a very pestiferous nature, written though they be in that "truly classic language which all mankind will eventually speak." Of the study of literature in general it may be observed, that therein we engage in the survey of the inner moving world of the human soul, and the more ideal and abstract (if at the same time moral) this be portrayed, the more humanising and morally edifying and beneficial it is in effect. In the study of the classic languages and literatures (notably the Latin), there is, in addition to this humanising element, the intellectual gymnastic, furnished by the various processes involved in the translation or constructing into English, or vice versâ. The eminent value of classical study lies, as it seems to me, in the combination of these two elements of culture. In the study of physical science, the humanising or moral element is wanting, or else feeble; in the study of our native literature the analytical intellectual faculty is not so vigorously exercised. No doubt there is what Professor Tyndall styles "an emotion of the intellect incident to the discernment of new truth;" but it is at best a rather dry and not very soft sort of sentiment. Indeed, Mr. F. Galton expressly avers that "the influence of scientific men is not directed to persons and to human interests, and they are deficient in the purely emotional elements," &c. I cordially endorse Mr. Williams's approval that physical science should be carried upwards to social and moral science, and I have read with the keenest interest his attestation anent the proceedings, in this particular, of certain worthy gentlemen and excellent scholars of Oxford. But Mr. Williams seems to include such studies as those of logic, metaphysics, moral and social science, in the same category with physical science. Most people will probably think that as regards educational efficacy they are widely different. The former are probably less humanising than literature and art; but they are of eminent value in this respect, and they are intimately allied thereto. Nevertheless, it would be idle to disparage the eminent utilitarian and intellectual benefits of the study and applications of physical science. Nobody nowadays yields allegiance to the ancient philosophy which, according to Seneca, teaches men "to be independent of all material substances and all mechanical contrivances." Our great aim should be that in the dispensation of this material knowledge its "celestial harmonies and breathings of paradise" be not utterly ignored and overriden. If only "the sublime consciousness of their own humanity" be more frequently stirred in the breasts of our eminent scientists, their influence over the age and the ignorant vulgar will doubtless be more elevating than it seems to be, and men would probably learn to reconcile forces (such as

religion, science, and practical work) which now seem diametrically opposed and mutually subversive. -P. Q. KEEGAN, LL.D.

I have only to add in explanation, that my objections to Homer and the poetry of the ancients apply especially to their use as school books. As historical records of one of the stages of human barbarism, they have great archæological interest, and the same may be said, in a minor degree, of the early English literature to which he alludes. In the dark ages when there was no other literature available, these old authors were desirable objects of study as literary models; but now that all the excellence of their art, minus the depravity of their morals, may be found in modern literature, I maintain that they should not be chosen for the education of youth.

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THE VARIATION

AND ABNORMAL DEVELOPMENT OF THE MOLLUSCA.

PART III.

TERRESTRIAL GASTEROPODA.

RION ATER.-A considerable number of forms occur; at Bedford Park, for instance, we find the type and varieties rufa, succinea, and nigrescens, as well as a form which does not agree exactly with nigrescens or plumbea, but is not distinct enough for a name; it is of a very dark slate colour, with a dark brown margin. The variety albida will probably turn up sooner or later, but I have not yet seen it. It has been found in Sussex and Herts.

At Chislehurst a form of var. succinea (yellowish, tinged with orange posteriorly, and with an orange margin), is found on the common among the brake fern and brambles; but in the old chalk-pit, in the lower Camden valley, amongst the coltsfoot, this form is replaced by the variety called pallescens, very pale yellow with an orange margin. Some of the little Arions are greenish, almost exactly the colour of the under-surface of a Tussilago leaf. The full description of one of these juvenile examples is : Tentacles dark brown, mantle yellowish-white, rather darker in front, body greenish-white, margin of foot yellowish-white.

A variety with a very dark brown mantle and a black body occurs at Chislehurst.

Arion hortensis.-A variable species, but (in our district at any rate) less so than A. ater. The ordinary banded form (called var. fasciata by Moquin-Tandon) is found at Acton, Chislehurst, Croydon, and many other places. The sole of the foot is sometimes of the most brilliant orange.

Some curious varieties are found at Bedford Park: one is larger than the ordinary form, and grey, with narrow lateral bands; another is dark above, and light at the sides, and others have already been described. ones Some very little were pale yellowish-red.

A number of Continental varieties of this slug have been described; one of the most interesting is var. virescens, which is greenish with black bands.

Arion, sp. ?-Intermediate in size between A. ater and A. hortensis; yellowish, inclining to orange, with brown bands placed in the same lateral position as those of A. hortensis. Three specimens under a log at Haslemere in company with A. ater, A. hortensis, and Limax maximus. I sent two of these to Mr. Roebuck, concerning which he writes as follows: "The Arions are of a very dubious sort, and I, like you, am uncertain what to call them . . . I have preserved your specimens in spirit, and pending the settlement of their specific name, I am calling them provisionally A. hortensis var. subfusca.”

They seem to be distinct from A. hortensis; and Mr. C. Ashford, who has dissected both these species, tells me that he finds slight but constant differences in their anatomy.

I have also taken this form at Chislehurst, where three varieties occur; the first is yellowish-white, the second purplish-brown, and the third yellowish-grey with a yellow margin.

I fancy that these Arions will be found all over the country in due time, and many of the records of A. flavus possibly refer to this species. I have recently found what I consider to be the true Arion flavus at Kingsley, Staffordshire. It is not unlike A. hortensis, from which, however, it differs in being orangeyellow on the sides and mantle and greyish on the back. There are faint lateral bands. The slime is orange-yellow and very thick. The sole of the foot is white and translucent. The respiratory orifice is a little in front of the central line of the mantle. Mr. W. D. Sutton, in the "Journal of Conchology," vol. i. p. 26, records what is evidently the same form from Northumberland and Durham; he says: "A variety (of A. hortensis) or possibly a species, nearly allied to this is found in woods. It is about twice the size of the garden slug, and its colour invariably yellowish fawn, inclining to amber, with a brown band on each side. The two kinds are not found mixed, one inhabiting the woods, and the other the cultivated grounds." However, I found the two kinds together at Haslemere, as stated above.

Limax agrestis.-In my notes I find recorded the following varieties :

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(3.) Mantle brown with very faint mottling, body greyish-brown. Croydon and near Godstone.

(4.) Mantle mottled with grey, body reticulated with grey just behind mantle, but mottled behind, head and tentacles light brown. Croydon. Intermediate between reticulata and sylvatica apparently.

(5.) Body and mantle light brown, spotted all over with grey at somewhat regular intervals; head and tentacles darker than ground colour of body. Chalk pit at Croydon. Possibly allied to var. punctata, Picard, but not, I think, identical.

(6.) Body distinctly and beautifully reticulated. One at Acton, others less marked, and approaching nearer to type (var. 4). This would seem to be var. reticulata. One at Croydon.

(7.) Ground colour light brown, body and mantle

Succinea Pfeifferi.-I have taken an almost scalariform specimen at Bromley. Var. brevispirata, Perivale, Middlesex.

S. virescens.-Specimens of this species from St. Mary Cray have the animal light in colour.

S. elegans. My brother has found some remarkably elongated specimens at Minster.

J. Hazay, in the German Journal of Conchology for 1881, gives a list of the species and varieties of Succinea Mrs. Fitzgerald has sent him from England. Among them he mentions the following-S. putris var. globuloidea, Cambridge; var. Charpentieri, Notts; var. limnoidea, Dublin; var. Ferrussina, Matlock; var. Fitzgeraldiana (var. nov.), Folkestone; Succinea elegans, type form, Essex and Deal; var. Baudoniana, Yorkshire; sub-sp. S. Pfeifferi, type, Folkestone and North Wales; var. elata, Cornwall; var. contortula, Yorkshire; sub-sp. S. suecica, Cheshire; S. oblonga, type and var. humilis, Cork. It would, however, be desirable to obtain speci

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Limax arborum." The beautiful sea-green variety occurs in a garden on Bramley Hill, where a family of them lives in a hollow in an old oak " (K. Mc Kean).

Testacella haliotidea.-It would seem that all the British individuals of this species belong to the variety scutulum, which may ultimately prove to be a distinct species. At Bedford Park there are three fairly distinct colour varieties. They may be described as follows: (A) ground colour pale yellow. (1) without any markings = pallida; (2) with brown mottling on back and sides typica. (B) ground colour orange = aurea. In aurea the mottling is as in the type form, and the orange of the sole is particularly vivid.

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Various varieties are found abroad. The Rev. J. W. Horsley has taken some at Gibraltar, which may be called scutulum, sub-var. albida, for they were pure white.

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mens of these varieties for comparison before admitting them into the British list.

Vitrina pellucida.—Not a variable species. My largest specimen is from Beckenham.

Hyalina.-The species of this genus are placed under Zonites by writers on British Conchology, but, nevertheless, I would reject that generic name for our British species in favour of Hyalina, Albers, and for the following reasons. The type of the genus Zonites is Z. algirus, L., a species totally unlike any of our British species, inhabiting the south of France, and ranging, it is said, to Constantinople. Kobelt gives fourteen species of Zonites proper, none of which are found in England, but have their home in south-east Europe. On the Continent, and I believe, in America, the so-called British Zonites are all placed in Hyalina, except fulvus, which is sometimes placed in a sub-genus Conulus. It is obviously essential that we should, if possible, use the same nomenclature as foreign conchologists, and when there is a difference of opinion, that of the majority should prevail, but as those who use Hyalina abroad are many more than those who use Zonites in Britain, it is hardly reasonable to expect them to change their name to please us, and all that remains is for us to adopt Hyalina.

The late Dr. Gwyn Jeffreys once wrote to me on this subject, he said: "I cannot accept the subgeneric name Hyalina or Hyalinia. . . Zonites represented by Z. algirus does not in the least differ from Hyalina.. By the rules of the British Association,

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adjective generic names (such as Hyalina) cannot be used."

Now as to Z. algirus not differing from Hyalina, Continental authorities are fairly well agreed that it does sufficiently to warrant a separate generic name, and I cannot help thinking likewise.

With regard to the other argument, it is absurd to suppose that the "rules of the British Association " are going to bind down foreign authors, and besides, what about Succinea? Nevertheless, Dr. Jeffreys' opinion is one that should not be lightly ignored, and so it will be interesting to see if any evidence can be brought forward against my view of the case.

I am greatly indebted to Mr. Ponsonby, of Halkin Street, for the opportunity of seeing his valuable series of British Hyalina, many of which have been sent to Dr. Boettger in Germany, and which have been returned with the names affixed to them, according to his view of the question.

Hyalina cellaria.-Common throughout the district. My largest specimen is from Kenley in Surrey, it is about three-eighths of an inch in diameter. This species resembles Hy. Draparnaldi closely, but I think they are distinct. The latter has not yet been found in our district. Var. compacta, Jeff., has been recorded. Var. albinos, Minster and Kenley.

Var. shell greenish-white and transparent. One at Maidenhead, a few on a mossy bank (the moss was, I believe, Polytrichum commune, L.) by the side of the high-road, between Wrotham and Eynsford. When I first found the single specimen, which was immature, at Maidenhead, I identified it as alliaria var. viridula, Jeff., as it had a strong garlic odour; but I find that the young of both cellaria and of glabra, Jeff., have a garlic odour, and as the shell is in shape exactly like a young cellaria, and like the more mature Kentish examples of the greenish var., I am obliged to refer it to cellaria.

I have referred the Maidenhead specimen to Dr. Gwyn Jeffreys, and he returned it with the note "The variety of Zonites cellarius is my albida." This being the case, it would seem that the milk-white and opaque var., which would also, I suppose, be var. albida (I have referred to it above as albinos, Moq.), is not to be separated from the greenish and transparent form.

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Hyalina glabra, Stud. (Jeff.).—Mr. Ponsonby submitted some of these to Dr. Boettger, who returned them as what the German conchologists called alliaria, and some of our British alliaria he called young cellaria, others young alliaria glabra, Jeff., and another British specimen he identified as Hy. petronella, Charp. Moreover, he sent some of what he called glabra, Stud., to Mr. Ponsonby, and these were, without doubt, perfectly distinct from the glaber of British conchologists. From this it seems that there is a great gulf between the British and German notions of the species of Hyalina; which we are to adopt seems uncertain, but it seems

extremely desirable that the matter should be cleared up. Jeffreys considered H. petronella to be the same as Hy. excavata v. vitrina, but Dr. Boettger's specimen is very different from this. In the British Museum some examples of Hy. glabra, Jeff., stand as

alliarius.

I have taken glabra, Jeff., in Kent and Surrey, in which counties it would seem to be abundant, but I fancy it does not occur in the Isle of Thanet. One specimen at Hanwell (S. C. Cockerell). I found a greenish-white and transparent variety (viridans of my note book) at Bromley, Kent.

Hy. nitidula. Common throughout the district. Var. Helmi, this is the white form; alba would have been a much better name for it than Helmii. Near Chislehurst, but rare. I found a curious variety at West Northdown, Thanet, having four whorls, the last whorl expanded, and shell larger than usual, and of a dull waxy appearance, slightly whitish beneath, and having a rather broad brown band below the periphery; band formula 00005.

Hy. pura.-The so-called "type" seems to be less common than the var. margaritacea, which is white. As far as I can remember, I have taken the type only near Godstone, Surrey, but I have found the variety at Farnborough, Addington, near Dorking, near Shiere, Haslemere; and Mr. Ponsonby has a specimen from Leatherhead.

(To be continued.)

CHAPTERS ON FOSSIL SHARKS AND RAYS.

CL

BY ARTHUR SMITH Woodward.

IV.

PETALONTIDÆ, CONTINUED.

[From page 156.]

'LOSELY related to Petalodus, and from the samegeological horizon, is Ctenopetalus, which differs in the shape of the root and the coarseness of the serrations; and not far removed, also, is the curious Polyrhizodus. This tooth (fig. 155) differs chiefly in being stouter and larger, in the absence of serrations on the cutting edge, and in having the root divided into a number of "radicles." Nothing is known of the arrangement in the mouth of either of these forms, and we are thus left to supply the deficiency by inference.

Proceeding to Petalorhynchus, which is also a Lower Carboniferous genus, we find the fossil remains a little more complete and instructive. Numerous specimens have been obtained from the Mountain Limestone of Armagh by the Earl of Enniskillen, and Mr. J. W. Davis published the results of his study of them in the Trans. Roy. Dublin Soc. for

1883. These teeth are of the same general type as those of Petalodus, but differ in several respects, and are notably longer and narrower, with the crown more spatulate. When one of them became useless in the mouth of the fish, and its successor was ready to come forward for active service, the old tooth did not fall out, but was always retained beneath the new one as a support; as the creature approached old age, the tooth in use had thus a considerable series of worn-out predecessors: beneath it, and these seem finally to have become more or less anchylosed together. Such series are not unfrequently found in the Armagh limestone, and one consisting of five teeth is represented in fig. 156; the lower and smallest tooth evidently indicates a young stage of the creature's existence, and as the mouth enlarged so did the dentition. The fact that some of these rows are symmetrical, while others appear "lefts" and "rights," suggests that they were originally ranged alongside each other; and there is reason to believe that one median tooth was present, with three on each side, but absolute proof is yet wanting of more than one pair occurring besides the median.

Still more interesting and satisfactory are the remains that have been discovered of the genus Janassa. This is typically a Permian form, often met with in the Kupferschiefer and the English Marlslate, but the researches of Messrs. Hancock, Atthey, and Barkas have revealed numerous beautiful examples in the Coal Measures of Northumberland and Durham, and Mr. John Ward has also recorded a few scattered relics from North Staffordshire. It ought to be remarked, however, that the Carboniferous forms were originally described under a distinct generic name, Climaxodus, and are often quoted thus; but there seems to be no doubt as to their identity with Janassa, and Münster's Dictaa is now likewise considered synonymous. Each tooth consists both of a cutting edge (fig. 158, a), and a crushing surface (ib., b), and, like other Petalodonts, possesses a well-developed root (ib., c). The dental armature of the mouth consisted of five of these teeth, ranged side by side, and flanked by a pair (fig. 157) that are indistinguishable from Petalodus, except perhaps in their obliquity; this arrangement is shown in fig. 157, taken from an elaborate memoir by Messrs. Hancock and Howse in the "Ann. & Mag. Nat. Hist." for 1869 (vol. iv. ser. 4). The vertical disposition of the teeth and their mode of succession is also known, and the same palæontologists published the illustrative diagram copied in fig. 158, from which it is obvious that, as in Petalorhynchus, the successive new teeth must have arisen from behind, and, on coming forwards, not caused the old ones to fall out, but have rested upon and utilised them as a support.

Taking into account these various well-ascertained

In this work will be found a full account of the Petalodontida, with references to previous literature.

facts, we arrive at the conclusion, that although the teeth themselves aremore like those of sharks than rays, their arrangement inthe mouth agrees most closely with the dentition of such typical rays as Myliobatis and Zygobatis, and the Petalodonts must thus be looked upon as probably intermediate forms. Something like a transition from cutting teeth to crushing teeth may even be noticed in the family itself, for Petalodus (Carb. Limst.) is exclusively laniary, Petalorhynchus (Carb. Limst. and Yoiedale) makes a slight approach towards the development of a tritoral portion, the so-called Climaxodus (chiefly Coal Measures) is adapted for both purposes, and the front cutting edge in some specimens of the Permian Janassa becomes almost obscured.

The curious teeth known as Ctenoptychius (fig. 159) and Harpacodus, also, most probably belong to the Petalodontidæ, and are both Carboniferous genera, the former ranging throughout all divisions, and the latter being exclusively confined to the lower. No definite evidence of their mode of disposition in the mouth has yet been obtained, and it ought to be remarked that certain small club-shaped fossils, originally referred to a species called C. unilateralis, are most likely not teeth at all, but Labyrinthodont scutes.*

PRISTIOPHORIDÆ.

According to Dr. Günther, this small family is only represented at the present day by species of the genus, Pristiophorus, which exist off Australian and Japanese coasts; these are little Selachians, with the snout much prolonged as in the next family, the "Saw-fishes," but having the gill-openings lateral. Fossil forms are rare, and the only im portant genus usually referred here is the remarkable Squaloraja of the Lias. A partly restored sketch of this fish is given in fig. 160, and among its many peculiarities may be specially noted the cephalic spine (ib., s), first described by Mr. William Davies, of the British Museum.† When a complete specimen is met with, this spine is generally so compressed and bent down upon the snout as to be rendered inconspicuous, but it is sometimes found detached, and occasionally (probably in females) it appears to be absent. The vertebræ are usually nothing more than calcified rings, and parts of the body are provided with dermal tubercles.

PRISTIDEÆ.

The "Saw-fishes " constitute a small family of rays, chiefly inhabiting tropical seas at the present day, and seem to have left no undoubted traces of their past existence in strata of an earlier period than the Eocene. They are particularly remarkable for

* T. Stock, "Ann. and Mag. Nat. Hist." [5], vol. viii. 81, PP. 90-95.

+ "Geol. Mag.," vol. ix. (1872), PP. 145-150, Pl. IV.

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