Preps. 12 and 13 illustrate the view that an elementary part consists of matter in two states,-active, as germinal matter, -passive, as formed material, which was once in the state of germinal matter.

LECTURE III.

APRIL 22ND.

Prep. 14. Shows the appearance of elementary parts (cells) from the liver of the mouse. Many contain two of the so-called nuclei, and some contain three or four. Nuclei are observed of all sizes, and the amount of formed material is very different in the different masses. In some elementary parts the outline is sharp and well-defined; in others it is rough and angular, and in some the outer part seems to be undergoing disintegration. No cell wall is to be demonstrated around these masses; some of them are very irregular in shape, having projections, and often much elongated, as if they consisted of soft material which had been moulded in a tube.

× 215.

Prep. 15. Shows the appearance of elementary parts from the liver of an old man, aged 74. The liver appeared healthy. The elementary parts are for the most part small, and there is not that very distinct line of demarcation between the germinal matter and the formed material which was seen in the last specimen, and which is in part due to the method of preparation. Oil globules and particles of colouring matter have been precipitated amongst the formed material. × 215.

Prep. 16. Contains elementary parts from a cirrhose liver. The quantity of formed material here is much greater than in the last specimen, depending probably on the changes which lead to the conversion of the formed material into bile, and other substances being interfered with. × 215.

Prep. 17. Epithelium from the tongue of a girl, aged 10. The youngest particles are seen upon the surface of a papilla, and are separated from each other by a very thin layer of formed material. The proportion of the germinal matter to the formed material gradually becomes less as we proceed outwards, until in the largest elementary parts seen in this specimen, which are by no means the outermost, the formed material is four or five times as wide as the germinal matter. The small dark red bodies crowded together are the deep elementary parts, and those above them and to the left are more superficial; the latter correspond to the side of the papilla. × 700.

The last four Preps. are intended to show that the structure external to, and resulting from, the changes occurring in the germinal matter, does not always take the form of a cell wall. The form of many of the elementary parts in Preps. 14, 15, and 16, is incompatible with the existence of an external investing membrane. In Prep. 17, the gradual growth of the formed material which, according to the theory entertained,

may be considered either as cell membrane and cell contents, or intercellular substance cr internuclear substance, is well seen.

Prep. 18. Perpendicular section through the mucous membrane of the tongue of a fœtus at the 7th month. Above is the mucous membrane with its epithelium. The papillæ are already formed, and their epithelial covering can be seen. At the lower part of the specimen the muscular fibres of the tongue are observed quite distinctly. Between the insertion of the muscular fibres and the deep surface of the mucous membrane is the corium, which seems to consist almost entirely of small oval particles of germinal matter, which are entirely colored by the carmine. Large bundles of nerve fibres and some vessels may with difficulty be discerned. There is only a trace of fibrous structure.

× 130.

Prep. 19. A corresponding section from the tongue of a girl, 10 years of age. Parts of two large compound papillæ are seen, and the corium has increased so much in thickness, that a very small part of it, with only a few of the pointed insertions of the muscular fibres are included in the field. The masses of germinal matter are very numerous in the papillæ, but in the corium they are fewer in number. These are the so-called nuclei of the areolar tissue (binde-gewebs-körperchen). × 130.

These two specimens are intended to illustrate the fact, that in a given bulk of young tissue there is a much larger proportion of germinal matter than in the fully developed tissue. In the fœtus there is comparatively little fibrous tissue to be detected in the corium. In the adult the corium seems to be composed entirely of this substance, the bundles of which are separated by yellow elastic fibres and corpuscles which are generally known as the areolar tissue corpuscles.

LECTURE IV.
APRIL 29TH.

Prep, 20. Deep surface of the cuticle from a blister on rising. The germinal matter occupies a much larger space than in the normal elementary part from the same situation. Several masses of germinal matter are dividing into two, and numerous constituent spherical particles are seen at the outer part of each mass of germinal matter. These are increasing, and exhibit a tendency to spread into the softened formed material. × 550.

Prep. 21. From the same blister 24 hours after rising. Numerous large spherical masses of germinal matter are seen now invested with but a very thin layer of formed material. These are very slightly removed from pus, and elementary parts of every shade of difference between the normal one from this part of the cuticle, in which the germinal matter bears a small proportion to the formed material, to the pus corpuscle, have been demonstrated in these preparations. × 215.

Prep. 22. Ordinary pus corpuscles tinged with carmine. The majority have escaped the action of the coloring matter. If the pus be allowed to remain long in the ammoniacal solution the corpuscles are entirely disintegrated. x 700.

Preps. 20, 21, 22, prove that the germinal matter of epithelium, the formed material which surrounds it, being softened so as to allow it to be freely supplied with nutrient matter,—will increase very rapidly, and if the conditions favourable to its growth last long enough, will assume the form of small spherical masses (pus), surrounded with, and separated from, each other, by a thin layer of soft formed material.

Prep. 23. Spherical masses of very actively growing germinal matter, closely resembling the pus in general characters. The specimen was obtained from a very simple form of fungus, which grew to the size of a small pear in a single night. Here it is impossible to detect any formed material forming an external envelope to each elementary part. × 215.

This preparation, like the last one of pus, exhibits numerous spherical masses of germinal matter with the smallest quantity of formed material, and is intended to illustrate the fact, that germinal matter, in the highest and in the lowest living structures, possesses the same general appearances, grows in the same manner, and may be stained with carmine. A small portion of the germinal matter from this rapidly growing fungus could not be distinguished under the microscope from that obtained from an elementary part of one of the highest animals. Germinal matter everywhere possesses the same character, and is always colored by carmine, but it differs widely in power.

Prep. 24. Tendon from the leg of a kitten, one day old, showing the very large proportion of germinal matter to the formed material.. The proportion diminishes as the tendon grows. × 215.

Prep. 25. Ridges and furrows of the skin from the tip of the finger, showing the formation of the papillæ, and the orderly arrangement of the elementary parts, composed almost entirely of germinal matter, from which the tissues are formed. The capillaries are injected with Prussian blue. Foetus 7th month. × 130.

Prep. 26. Bulbs of the hairs of a kitten. The capillary loop in the papilla is injected blue. Observe the quantity of germinal matter and the small amount of formed material at the lower growing part of the hair, and compare the appearance here with that existing higher up. × 215.

Preps. 25 and 26 illustrate the fact that even in young tissues, before any textural peculiarities are manifested, the separate portions of germinal matter grow in a regular and orderly manner, and do not multiply beyond the boundaries assigned to them.

LECTURE V.
MAY 6TH.

Prep. 27. Section from a large tumour from the back of a boy, aged 2 years. It grew from three to twenty-seven inches in circumference in about six months. The boy died eleven months after the tumour first appeared, from exhaustion consequent on hemorrhage. The tumour weighed 12 lbs. It probably originated in the periosteum, at the inferior angle of the scapula. × 130. (Case reported by Dr. Elin, of Hertford.)

Prep. 28. Cancerous tumour from the parotid. The remains of some of the follicles of the gland can be seen. These being dead, and in a state of disintegration, are not colored by carmine, but, in the actively growing tissue, the proportion of living germinal matter to the formed material is very great. So active is the power of increase that the elementary parts insinuate themselves between tissues in every direction, causing their death, and appropriating the material of which they were composed. × 130.

Prep. 29. Elementary parts (cancer cells) passed in the urine in a case of cancer of the uterus. The germinal matter is very abundant and well colored. (Sent by Dr. Arthur Farre.) × 215.

Preps. 27, 28, and 29 show that cancerous growths, like healthy structures, are composed of elementary parts, each consisting of germinal matter within, and soft formed-material externally. An elementary part from a cancer (cancer cell) sometimes cannot be distinguished by any microscopical characters from the elementary part of a healthy tissue, but it differs from it in the irregularity and greater rapidity of its growth, and in the continual repetition of the same processes, leading to the indiscriminate destruction of higher tissues. In the normal state, growth occurs under certain restrictions, and in adult tissues the removal of the old elementary parts is exactly_counterbalanced by the orderly development of new ones. In certain morbid states, these restrictions are almost entirely removed, and the formation of new tissue, which goes on uninterruptedly, is only limited by the supply of nutrient material.

Prep. 30. Old and young elementary parts from the common potatoe, close to the point at which a bud is being formed. The germinal matter (primordial utricle) is well colored, and can be distinguished from the formed material external to it (cell wall, intercellular substance), and from the secondary deposit in its central part (starch globules, in the present case).

× 215.

Prep. 31. Portion of the young leaf of the common mignionette, showing the elementary parts, composed externally of formed material and of germinal matter within. The nucleus is observed to be very darkly stained with carmine.

Prep. 32. A portion of the epidermis from the leaf of the common mignionette, showing the germinal matter and formed material.

Prep. 33. A small piece of a rootlet of the common mignionette, showing that the elementary parts of which it is composed, like those in the leaves, consist of germinal matter and formed material. A small portion of the germinal matter (nucleus) is seen of a much darker color than the rest, as in many of the animal tissues.

Prep. 30 shows the manner in which products resulting from changes in the formed material, secondary deposits, may be deposited amongst the germinal matter and this, with Preps. 31, 32, and 33, prove that the vegetable elementary part, like all others, may be considered to consist of germinal matter and formed material.

LECTURE VI.

MAY 13TH.

Prep. 34. Tendon of child at birth, showing elongated masses of germinal matter colored with carmine, and the intervening formed material (intercellular substance) colourless. In parts of the specimen, the continuity of the fibrous matter, or formed material, with the germinal matter can be most distinctly seen. The germinal matter passes into the formed material.

Prep. 35.

× 215.

Vessels of Tendo Achillis; kitten, one day old. The vessels are seen to be very numerous in this preparation. × 215.

Prep. 36. Tendon from the finger of an old man, aged 74. The relation of the germinal matter to the formed material is the same as in the other specimens, but its proportion to the latter is very much less. When the fibres are stretched in a longitudinal direction, the oval masses of germinal matter appear as very narrow red stripes, which communicate with each other by a narrower and much fainter line (nuclear fibres, kern-fasern). On the other hand, when the fibres are stretched laterally, the oval masses become very broad, and may be made, by stretching, almost circular. In this state, longitudinal cracks or creasings are observed, and the lines of germinal matter can be seen most distinctly to be continuous with the formed material. × 215.

Prep. 37. Fascia from the frog, showing the connection of the oval masses of germinal matter (nuclei) with the formed material (fibrous tissue, intercellular substance). × 550.

Preps. 34 to 37 are intended to show that the fibrous tissue of the tendon, or formed material, is in immediate connection with the masses of germinal matter, and the constant variation in the relative proportion of the germinal matter to the formed material in the young and old tendon in all animals establishes a definite relation between the two structures. The whole of the fibrous tissue, or formed material, was once in the state of germinal matter. The masses of germinal matter, which are colored red in all these specimens, and which exactly