THE CELL-THEORY 



273 



gelatinous connective tissue, which is, as he justly observes, the early 

 form of fcetal connective tissue generally. (1. c, p. 58.) If the outer 

 layer of the corium of the skin, or the submucous gelatinous tissue in 

 the enamel organ, be teased out with needles, we shall obtain various 

 stellate or ramified bodies containing endoplasts (fig. 4), which Kolliker 

 calls cells, and which, as he states, do assuredly pass into and become 

 bundles of fibrillated connective tissue. But is this really a different 

 mode of development from that already described ? We think not. 

 Indeed, if that portion of this young 

 gelatinous connective tissue, which lies 

 immediately adjacent to the epidermis or 

 epithelium, be examined, it will be found 

 to present a structure in all respects similar 

 to foetal cartilage, that is, there is a homo- 

 geneous matrix in which the endoplasts are 

 dispersed (fig. 5, B). If this be traced in- 

 wards, it will be found that the endoplasts 

 become more widely separated from one 

 another, and that the matrix in places 

 between them is softened and altered, while 

 in their immediate neighbourhood, and in 

 the direction of irregular lines stretching 

 from them, it is unaltered. This is, in 

 fact, the first stage of that process which 

 we have called vacuolation. In this con- 

 dition the intermediate softened spots still 

 retain sufficient consistence not to flow out 

 of a section ; but yielding, as it. does, in 

 these localities, much more readily than in 

 others, it is easy enough to tear out the 

 firmer portion in the shape of " cells," which 

 are fusiform, irregular, or stellate ; and the 

 whole tissue has therefore been described 

 (Reichert, Virchow, Schwann) as consisting 

 of cells connected by an " intercellular sub- 

 stance." Both " cell-walls " and " intercellular substance," however, 

 are portions of the same periplast, and together correspond with 

 the matrix of the cartilage. When, therefore, in the course of 

 further development, the " intercellular substance " becomes quite 

 fluid and so disappears, the outer portion of these cells being con- 

 verted into fibrillated collagenous tissue, and the inner into elastic 

 .substance, we have, notwithstanding the apparently great difference 



T 



Fig. 5. 



Submucous tissue and epithe- 

 lium of the tongue of the 

 kitten. A, Epithelium ; B, 

 young connective tissue. 



