At its form during pregnancy, that of the cavity of the body undergoes marked alteration. a certain period after fecundation, it exfoliates cell by cell or by flakes, and is replaced by the polyhedral pavement form of epithelium, the cells being of from twelve to eighteen-thousandths of a millimetre in size, containing a spherical or ovoid granular nucleus of about the size of a red blood-globule, but, as a rule, no nucleolus. Many cells are void of nucleoli, and are uniformily filled with yellowish fatty granulations, and this condition of the cells is found on the decidua vera and reflexa. After two months and a half of pregnancy, other cells, much larger and longer, are seen in addition. These are delicately flattened, from four to nine-thousandths of a millimetre long, always irregular, and prolonged at the extremities or angles. They possess a large ovoid granular nucleus, certain slight scattered granulations, and increase in numbers towards the end of gestation. As pregnancy advances, the nucleus of the large cells, which about the second or third month of gestation is often wanting in a nucleolus, obtains one or two, which are yellow and shining in the centre, with a definite contour; and the nuclei have also become very large. In the region of the upper part of the neck of the uterus, where the decidua reflexa at the eighth month is not adherent, cellules like those above described are to be found, some being regularly polyhedral, others elongated, and all containing nuclei of an ovoid or spherical shape, which are from twelve to fifteen-thousandths of a millimetre long, and generally furnished with one or two bright nucleoli. Some of the cellules maintain their prismatic form, but the adherent extremity is generally rounded and swelled. At this period of pregnancy the epithelium of the Fallopian tube is chiefly composed of nuclear epithelium, formed of ovoid, sometimes spherical nuclei, and united by a small quantity of amorphous material. The author then goes on to speak of alterations undergone by the epithelium enclosed between the placenta and the vascular part of the uterine mucous membrane, and that covering the uterine and reflected decidua, where brought into contact by enlargement of the . ovum. In these places the epithelium is partly formed of free nuclei and in part of cellules. The latter are partly like those described, and some, although half or double as large as others, yet maintain the prismatic form, and are rounded at their extremity. Others, again, become polyhedral, and in almost all, the nucleus has increased proportionately with the cellule, containing one or two nucleoli having a brilliant centre and dark contour. But in addition to these cellules others are found, isolated or forming lamina, which are of variable size up to about one-thousandth of a millimetre or more. For the most part they are elongated, and generally irregularly truncated, rarely being sharpened, and at times ovoid or fusiform. Sometimes one or two of the extremities are bifurcated, and this is especially so at the angles of the cells which remain more or less polyhedral. Some are to be seen with two or three nuclei, although they generally possess but a single one, which is very large, ovoid, and having a clear bright centre and regular clear outline. Each nucleus contains one or two nucleoli. The free nuclei of the epithelium are very like those ordinarily named cancerous or carcinomatous, and would be so designated by those not conversant with the subject. These large defined cells are mostly filled with granular fat, situated chiefly around the nuclei or at the ends of the cells, a few remaining finely granular, pale, and transparent. The author concludes by drawing a strong analogy as to structural form between the above described natural condition, and certain pathological states for which they might readily be mistaken. On the Central Parts of the Hair in a Physiological and Pathological state.-Dr. A. Spiess* controverts accepted views as to the structure of the hair, and applies his own description thereof to the elucidation of diseases of this structure. He takes exception to the statements of Kölliker, that the central material of the hair, is composed of a row of cells containing a tenacious substance with air-holding cavities; of Steinlin,† who looks on it as a projection of the hair papillæ into the hair; of Reichert, who also considers it as a projection of the papillæ, which at the lower part of the hair serves the purpose of a matrix for the hair to be developed around it, and afterwards degenerates into a species of pith, as in the case of feathers, and which also often contains air, although this also exists free between the cells. In opposition, Spiess states that the medulla of the hair is only a canal in the centre for the most part containing air, in which the remains of dried cells exist. He also opposes the statements of Engel as to the method by which hair after section again grows and recovers its point. In a thin hair a certain quantity of nourishing fluid is, according to him, secreted from the vessels of the hair papillæ. This nourishes the root, and passes upwards between and nourishes the cells throughout the hair. At the same time the cells give out the used material, to be again reabsorbed in the follicle below and above, to be cast off as a powder. This fluid, if the hair is not long, goes to form new cells in the root, and thus the hair grows, the Henle und Pfeuffer's Zeitschrift, Band v. Heft 1. 1858. Zeitschrift für Klinik Med., Band vi. Heft 1, p. 1. 1855.3 + Ibid., 1850. cells dwindling and passing into the cortical part as they progress upwards from the root. In thick hair, however, as there exists such an impediment to the passage of the refuse material from the middle parts that they remain in the centre, only the outermost parts being nourished, the central cells shrink, become atrophied, and disappear in part, or remain as débris, whilst their place is occupied by the refuse material forming the medullary part, which consists of cell-remains, gases, and in part fluid. The thick hair consequently consists of only a cortical substance, composed of compressed fibre-cells covered by a pellicle, having a canal in the centre containing hair and fluid, but no medullary substance. The four pathological cases adduced in connexion with the above statements as to the elements of hair, illustrate morbid changes in various portions of the hair, and in hair of various thickness. NERVOUS SYSTEM AND ORGANS OF SENSE. On the Termination of Nerves. By Dr. W. Krause.*-The author made his observations chiefly upon the conjunctiva of the ball of the eye, as affording the best opportunities, owing to the delicacy of its epithelium, its freedom from pigment, hair, glands, papillæ, or strong elastic fibre, &c., and by reason of its abundant supply of nerves with dark contours. Having separated a piece of the conjunctiva from the subjacent tissue of the warm eye of a recentlykilled calf, the nerve branches are seen forming a rich plexus by subdividing anastomoses, the single fibres of which gradually diminish. In the smallest branchlets, formed of two or three fibrils, numerous bifurcations of the fibrils inay be seen, which finally either arch in order to end immediately, or preserve their course, anastomosing with other fibrils or their branches. Most of the fibrils bifurcate at various angles once more before terminating; more seldom they divide into three. Whenever their terminations can be seen, they will be found to end in a peculiar small, round, or oval corpuscle, with a thicker and a finer extremity, called by the author the terminal bulb. These latter bodies consist of an investment of areolar tissue containing nuclei, and a soft cylindrical mass of faintly glistening substance, in which the double-contoured nerves end, and in the centre of which is embedded an axis fibre-a stripe with a slightly thickened extremity-the investment being an immediate connexion with the neurilemma of the fibril, which before the termination of the latter is slightly elevated. The investment is beset with elongated and often spindle nuclei at the sides and end of the bulb, and in the larger terminal bulbs very fine blood capillaries may sometimes be seen in the investing membrane. The nerve-fibrils in the calf, before their entrance into the terminal bulb, possess a breadth of from to" (Paris), and get smaller, until they are only from to in size. The axis fibre itself measures from" to "in breadth; the final swelling of the fibre being about "broad. The dimensions of the entire final bulb are from "" to as to length, and from" to "" in breadth. Apart from the size, these bulbs have a closer analogy to the Paccinian bodies, excepting that they are wanting in the concentric lamella which in the latter surrounds the central substance. The form, however, of these bulbs is not always regularly cylindrical, but at times arched and pear-shaped, indented, &c. They are situated partly in a horizontal direction, immediately beneath the firm areolar layer below the epithelium, and partly more or less in a perpendicular direction to it, with their thicker ends towards it. The author thought he had met with divisions of the axis-fibre and the whole bulb analogous to that of the Paccinian corpuscle. These terminal bulbs soon undergo decomposition, and twenty-four hours after death only a fragment of the axis-fibre remains visible, the whole having become clouded, and at times streaked and fatty. Acetic acid renders the nuclei more distinct, but obscures the axis-fibre and entire bulb. An alkali makes the bulb pale and swollen, the axis-fibre dwindling, and very dark fine fat granules appearing in the interior. The nerve-fibres are, however, in this way brought out in their course. In the case of preparations which have been some days in a solution of chromic acid, the addition of an alkali renders the whole bulb very clear, but for a short time only. These terminal bulbs have different measurements in different animals, as will be seen in the following statements: 1 !!! 350 1 /// 26 1 400 In the deer the bulbs are about in length, and from to 1"" in breadth. 1 ΤΟ 80 60 1/ TE to To 1 18 84 to 30 "" to To Occasionally there are seen windings of the double-contoured nerve-fibres which enter them. As to the number of these bodies existing, it was found that in the case of the calf, a space Henle und Pfeuffer's Zeitschrift, Band v. Heft 1, p. 28. 1858. about 1" in length and 1”” in breadth gave as many as ten of them; and in the deer and sheep, in the same given space, a branchlet with three nerve fibrils was seen after numerous divisions to possess the number of twenty-three. In the conjunctiva of the common hen, small Paccinian bodies, as in the tongue of some water birds, were met with. 1 70 360 1 600 1 70 In man, nerve-knots (knäuel), consisting of numerous interlacements of one or more nervefibrils, are met with in the conjunctiva, measuring about" in length, and "" in breadth. They are often spherical, and in some cases possess loops of fibrils on the surface. The terminal bulbs, in man, are rounder than in animals, often almost spherical. The investing membrane, with its nuclei, resembles those above described as to behaviour with reagents, &c.; but the entrance of nerves is, however, considerably modified, and very often the bulb is placed symmetrically upon the nerve-fibril as on a stalk. Or the nerve forms a hook or crook-like bend, and the bulb is placed upon it laterally. The fibrils also may be twisted singly, or numerous convolutions may exist within the investing membrane of the terminal bulb. Sometimes a fibril bifurcates, and each subdivision then enters the bulb, and ends either immediately or after making several convolutions. Under favourable circumstances, firm pale fibres about " in diameter are seen to proceed out of the above-mentioned knot of nerves within the bulb, and to end inside the bulb after numerous twistings. In these cases there are more axis-fibres inside the bulb, reminding one of the Paccinian corpuscles observed by Kölliker* in the case of the cat. In man the bulbs measure from "" to " in length, and from "to" in breadth; and the diameter of the nerve-fibril before entering is about " to ", whilst after entrance it measures from "to". Other parts besides the conjunctiva contain these terminal bulbs. Thus, in man they are found in the mucous folds beneath the tongue, the soft gums, the fungiform papillæ, and under the base of the filiform papillæ, and in the papilla of the red edge of the lip, in the mucous membrane of the glans penis and clitoris. They are to be met with also in the tongue and lips of the deer, in the glans penis and clitoris of the pig, in the sublingual mucous membrane of the cat and rat, in the volar surface of the toes of the guinea-pig. In all these cases they are placed more or less inclined at an angle to the surface. In these localities the bulbs do not enter into the microscopical papillæ, excepting in the lip and perhaps the soft gum of man, where they are found at the termination of the papillæ. In the mucous folds at the bottom of the mouth of man they are very large, being " long and broad. In the glans penis and clitoris of man the investing membrane of these bodies is very thick and firm, and very deeply situated beneath the papillæ. In the glans penis, &c., of the pig they are very abundant, and very similar to Paccinian bodies, having been described as such by Kölliker and Hylander, possessing a thick laminated investing membrane, but no special capsule. The author then gives the various measurements of these bodies as found in different parts of animals, and proceeds to give his views as to the function of these bulbs. He thinks they are evidently concerned in the conduction (vermittlung) of simple sensibility, the investing membrane only serving for protection, and the nuclei being probably connected with nourishment. The knot-like convolutions and bifurcations appear to have the purpose of intensifying sensation. He then passes in review the terminal corpuscles of nerves in various organs which may be looked on as transitional steps one from the other, beginning with the Paccinian corpuscle of the maminalia, advancing through those of the bird to the "terminal bulbs" of mammalia, and thence through the "terminal bulbs" of man to the sen sitive corpuscles (tast-körperchen) of man and the monkey. The terminal bulb of the mammalia seems to show the simplest form, consisting of a fine terminal axis-fibre surrounded by the soft conducting substance of the corpuscle, and invested by a nucleated membrane. Then we have in the Paccinian bodies of birds peculiar transversely-spiral fibres between the central fibre and outer investment. In the Paccinian corpuscle of mammalia appear numerous concentric lamella which are to be considered as a conducting apparatus; and the 'terminal bulbs' of man are to be looked upon as a further development of the simple structures existing in mammalia. The tactile corpuscles (tast-körperchen) consist of a delicate areolar investment containing nuclei placed transversely and lengthwise, and a quantity of soft granular contents. In the interior, the entering ner fibres divide into numerous tuft-like axis fibres, which contain a semi-fluid substance, and which are the sensitive part of the corpuscle. The author quotes his father, as well as H. Henle and Meissner, as supporting the above described observations. OSSEOUS SYSTEM. On the Development of Bone-substance in Plasmatic Fibroid Tissue.-The subject is treated * Zeitschrift für wissensch. Zoologie, Band v. p. 119. 1854. by Dr. C. Ronget in a paper,* illustrated by plates, on the corpuscles of bone and on the development of secondary bones. After alluding to the controversy regarding the supposed method in which the bone-substance is formed where no cartilage previously existed, whether, for example, the calcareous matter be deposited in a continuous membranous blastema of which but certain parts become ossified, or in an alveolar cartilaginous framework-or whether, again, the cellules of the blastema be transformed into osseous corpuscles, or whether the latter be only cavities formed either at the expense of the interstices of the cartilaginous framework or directly by ossification-the author proceeds to detail the results of his own examination of the subject. He states that in the human embryo of ten or twelve weeks, if the fibrous membranes (the periosteum and dura mater) between which the bones of the cranium are developed, be carefully examined, a lamina partly osseous and partly membranous may be obtained, which is continuous throughout the whole extent about to be occupied by the perfectly formed bone. The membranous zone is in direct continuity with the zone in course of ossification, and, like it, is quite distinct from contiguous fibrous structures. In each lamina already four distinct regions may be recognised. Of these, two occupy the extreme limits, the one completely membranous and homogeneous in structure, the other completely osseous. Of the two middle ones, the one contiguous to the osseous region is itself in process of ossification, whilst the other, which is contiguous to the membranous region, presents certain peculiarities, and this zone the author designates the intermediate zone or region. The membranous zone is formed of a fibroid and granular connective tissue, traversed here and there by decussating fibrous bundles, and characterized by innumerable rounded or ovoid plasmatic cellules and free nuclei. In the intermediate zone the same elements exist, but in addition a network of transparent and homogeneous hyaline trabeculæ, which appears to repeat the disposition observed by the inter-crossing bundles of the membranous zone, with which it is manifestly continuous, but by a gradual fusion of the characteristics of the two elements. Towards the zone in course of ossification the trabeculæ multiply, become thicker, and circumscribe large and small spaces. At the limit of the two regions the trabecule of the hyaline framework are continuous with trabeculæ quite analogous as to general disposition, but differing in appearance, being less transparent, and occupied by yellowish granulations and innumerable microscopic cavities; and a decided line of demarcation exists between the extremities of the trabeculae in course of ossification and the hyaline trabeculæ, although both cavities belong to one and the same system. The web-work which is undergoing ossification intercepts two kinds of meshes distinguishable by their peculiar dimensions. Of these, the one forms veritable areola, the other small microscopic cavities, both possessing trabecular walls either hyaline or in course of ossification, and containing connective blastema and cellules. On approaching the perfectly ossified zone and the more obscure and yellowish trabeculæ, the minute cavities in the thickness of the trabeculæ become more and more small, and a hyaline network, which speedily becomes ossified, extends in the areola, which it closes or obliterates. Where, also, the hyaline framework becomes involved, groups of cellules, more or less numerous, and one or two isolated cellules, insinuate themselves in the inter-cellular connective substance. Thus, when the primitive membranous layer has undergone perfect transformation, we have a transparent homogeneous blastema gradually poured out in the granular and fibrous connective substance, and in this blastema subsequently are deposited the elements of ossification, whilst during all these changes the plasmatic cellules of the connective tissue remain intact within the small irregular cavities of the new osseous substance. In this way, in the place of a membranous blastema, whose elements appear only at the period of ossification, it must be admitted that there is a pre-existence, at the spot where the osseous substance is primarily developed, of a fibrous or fibroid membrane, which at first occupies all the space possessed at a later period by osseous formation. True it is that an areolar hyaline framework gradually precedes the calcareous deposit, but there is no reason for looking upon this framework as being cartilage, for it is wanting in cartilage cellule, and the persistence of the prismatic cellules in the midst of this framework shows it to be a simple modification, a return to the primitive form of the connective inter-cellular substance. Throughout the paper reference is made to the late theories of Kölliker and Robin, and most authors who have written upon the formation of bone, as well as to the views of Reichert, Virchow, Donders, &c., as to the original identity or homology of the various plasmatic or connective tissues of cartilage, bone, fibre, medullary tissue, &c. THE BLOOD. On the Modifications undergone by Blood-Globules of certain Animals injected into the Circula* Brown-Séquard's Journal de la Physiologie, p. 764. Oct. 1858. tion of other Animals, &c. By Brown-Séquard.*-This physiologist has observed, on examining by the microscope the blood of the dog, cat, or rabbit, even a single hour after injection therein of the blood of the bird, that none of the oval large globules are to be met with; and if examined some days, or even several hours, after, none whatever are to be seen in any organ of the body where it might be supposed that they had been arrested. The blood, however, of such an animal, if examined a quarter of an hour after the injection of the bird's blood, will be found to contain oval globules in the veins of all the organs. Thus it appears that all the capillaries of the body are permeable by and do not arrest these large oval globules. But, even for the space of a month after injecting the blood of the dog, rabbit, guinea-pig, &c., into the circulation of the bird, some of the circular discs are to be seen within it when examined by the microscope. In the case of the cock, into whose veins dog's blood has been transfused, on the following day as many round as oval globules are to be seen; but in a few days the circular globules have become much fewer, and three weeks after only two or three are to be seen in proportion to a thousand of the oval ones. On certain Peculiarities in Form and Size exhibited by the Red Globules of Blood in Embryos. By Dr. C. Robin.t-According to this author, the red globules in the embryo of man, from the time of their appearance to the period when the body has attained the size of twenty-five millimetres or more, possess a diameter for the most part of eleven thousandths of a millimetre, their thickness being from three to four thousandths, unless when rounded by contact with water. In the embryo of three millimetres in size, a few are only eight thousandths of a millimetre, the most being from eleven to thirteen thousandths. In an embryo of twenty-five millimetres long, some of the globules were from seven to eight thousandths, and some from fourteen to sixteen thousandths long and three thousandths in thickness. In an embryo of nineteen millimetres long, in addition to red globules of the above size, there were a number sixteen or seventeen thousandths in size, with a thickness of five thousandths. In embryos from three to twenty-five or thirty millimetres long, most of the globules are discoid and biconcave, and often thicker at one point than another; but some are spherical, and some are ovoid but not flattened, measuring seven, eight, or ten thousandths of a millimetre long by from twelve to fifteen thousandths. Some have a wallet shape, with a contraction towards the centre, and at this age the red globules are remarkable for the facility with which they may be put out of shape by reciprocal pressure, or when compressed in small capillaries, &c.; but they are very elastic, speedily assuming their natural shape. The above particulars hold good in all domestic mammalia and rats. In very young embryos the red globules change very quickly after death, from being discs, becoming in many cases hemispherical or spherical, then softening, becoming diffluent, and running one into the other; some also become indented and plicated irregularly, the circumference of the globule becoming generally irregular. The author proceeds to speak of the nuclei of embryonic, blood-globules. In almost but not quite all embryos, from the time that the globules are first found to that when the embryo attains twenty-five or thirty millimetres in size, these globules contain nuclei; but about that period nearly half of the globules are deficient in any nucleus, and the number of these goes on increasing. At the fourth month of intra-uterine life occasional globules contain nuclei, but after this time none are to be seen containing them. The globules which towards the fourth month retain a nucleus are from one to four millimetres longer than surrounding globules. As to the nucleus itself, it is spherical, of three or four thousandths of a millimetre in size, greyish, insoluble in water, as also in acetic acid, which contracts it slightly, and renders its edges clear and its centre brighter. It is finely granular, and without any nucleoli, and pretty often situated at a point slightly removed from the centre. When placed centrally, the nucleus masks the central depression of the discs, which, when the nucleus is on one side, is well seen. The embryonic blood-globules which possess nuclei contain, especially in the herbivora, one, or rarely two, very small fatty granulations, often disappearing after distension with water. PART II.-PATHOLOGICAL MICROLOGY. TUMOURS, MORBID GROWTHS, EXCRESCENCES, ETC. Papillary Tumour.-M. Maier, of Freiburg, communicates at some length the history and description of a tumour of this nature. It was removed from a man aged seventy-six, who * Journal de la Physiologie p. 173. Jan. 1858. + Brown-Séquard's Journal de la Physiologie, p. 285. April, 1858. |