310 SPECIAL HISTOLOGY. 



102. Metamorphoses of the primordial cartilaginous Skeleton. Of 

 the primordial cartilages, one portion undergoes further development 

 with the rest of the skeleton, constituting the permanent cartilages of 



be described more at length. We found the cartilage of the septum nasi of a four-months' 

 human fostus to be composed of a homogeneous, soft matrix, without structure of any kind, 

 in which lay imbedded, rounded or irregular vesicular bodies, varying in diameter from 

 otHTirWW 111 of an inch 5 tne commonest size, however, being y^^-^^^th. These 

 t; corpuscles" frequently contained one or more granules, sometimes very small, sometimes 

 larger, and of a distinctly fatty nature; such fatty granules, also, were sometimes to be found 

 in the matrix around the corpuscles. 



The cavities in which they lay, were, for the most part, just large enough to contain them, 

 and presented no walls or sharp lines of demarcation of any kind from the surrounding 

 substance. 



When the corpuscles were as large as j^^th of an inch, they occasionally contained a 

 round body of rather less than y^^th, as a " nucleus." 



The matrix was in some parts pale and indifferent ; but where the tissue had taken on 

 its definitely cartilaginous nature, the chondrinous substance into which it was converted re- 

 fracted the light much more strongly. In this part also, the cavities in which the corpuscles 

 lay, were often of considerably larger dimensions than the latter, and their walls exhibited a 

 sharp, dark line of definition from the surrounding substance, which was often brought out 

 much more strongly by the action of acetic acid. It appeared, in fact, that the conversion 

 into chondrin had not quite reached the inner surface of the cavities, and hence they were 

 chemically and optically distinguished from the surrounding substance. 



Now, of course, it matters very little what names are given to these parts, so long as they 

 are used only in one sense. Schwann considered the corpuscles to represent the " nuclei" of 

 plants, and therefore gave them that name. Henle, Reichert, Kolliker, and nearly all their 

 compatriots, Todd and Bowman, Leidy and Sharpey follow him. As a consequence, they 

 consider the wall of the cavities to represent the cellulose "cell-wall" in plants ; and there 

 has been much controversy as tp how much of the matrix of the cartilage results from the 

 union of these " cell-walls," how much from the development of an intercellular substance ; 

 a controversy which has extended itself to the determination of the homologies of the ele- 

 ments of every tissue. We must confess, it seems to us that the disputants have been 

 fighting for a shadow. 



If, in fact, the youngest cartilage be composed of cells with distinct walls enclosing the cor- 

 puscles, of course these cells may be united by an intermediate, " intercellular" substance ; 

 and it will be an important question to determine in the further course of development 

 what arises from the walls and what from the substance which unites them. But if, on the 

 other hand, all this be pure hypothesis; if young cartilage be, as we have said, composed of 

 nothing but a continuous, homogeneous matrix, in which the corpuscles are imbedded, but 

 in which no other structure exists, what becomes of the controversy ? 



We believe that not merely will the account we have given, be found to be correct, by 

 any one who will without prejudice examine into the subject, but it seems to result from the 

 observations, even of those who have interpreted the facts otherwise. 



Schwann ("Mikros. Unters.," pp. 112, 113) describing the development of the cartilage of 



Pelobates, says : " The new cells arise in the cytoblastema (matrix nobis) We see 



at first mere cell-nuclei (corpuscles nobis), which are somewhat smaller than the nuclei of 

 the full-grown cells, a, 6; partly nuclei, which are closely surrounded by a cell, t, c ; in 

 short, all transitional forms, from mere cell-nuclei and nuclei surrounded by small ells, to 

 fully formed cells ; so that here, development takes place as in small cells, and the nucleus 



is their actual cytoblast The cell-membrane becomes distinct only in the full-grown 



state." 



In the next page, Schwann speaks of the free-swimming nucleated corpuscles which he 

 obtained from the ossifying cartilage of a fcetal pig, and which he considers to be identical 

 with the bodies already described in Pelobates. In reality, however, these bodies are not 



