82 GENERAL ANATOMY OF THE TISSUES. 



Literature. — C. B. Reichert, ' Vergleichende Beobaclitungen 



iiber das Bindegewebe und die verwandten Gebilde/ Dorpat, 



1845; Luschka, 'Die Structur der serosen Haute.' Besides 



which, consult the works of Virchow, Donders, Rernak, and 



myself, cited above. 



with the development of the " fihrillated" collagenous suhstance is, however, obvious, 

 from this very simple circumstance — that the latter lies between them, and in part re- 

 places the rest of the matrix of the cartilage, into which it can be directly traced. It will 

 not be said in this case, that the "fihrillated" tissue of the tendo-Achillis is only "decep- 

 tively similar" to true connective tissue — and yet the transition of true cartilage into true 

 connective tissue, is not less certainly demonstrable in the intervertebral cartilages, &c. 



As Reichert, then, long since indicated, in illustrating his "law of continuity," 

 (a law whose full importance, it may be observed, has yet to be developed), and as 

 he and Virchow have since demonstrated, the elastic element of fully-formed con- 

 nective tissue represents the cartilage-cells, while the collagenous element repre- 

 sents the matrix of the cartilage, and is not developed from distinct cells. 



With regard to the structure of the latter element, Reichert, in his last communi- 

 cation, after considering Kcilliker's arguments, denies the truth of his statement, that 

 the ends of the fibrils may be seen in transverse sections of the tendons ($ Tendon, 

 infra), and retains his opinion that it is not truly fihrillated in the uninjured state, 

 but that it is simply plaited. Some remarkable observations upon the behaviour of 

 the " connective fibril bundles" with acids and alkalies, to which Reichert first drew 

 attention in 1846, and which have been since extended by Dr. Paulsen (Bericht., 

 Midler's 'Archiv,' 1849), are, as the former points out, of the greatest importance in 

 determining the nature of this tissue, and remind one somewhat of the equally 

 puzzling structure of the starch-corpuscle. Dr. Paulsen states, that if a piece of 

 tendon be kept for twenty-four hours in a solution of caustic potass of 10 per cent, 

 strength, it changes into a viscid hyaline mass, so transparent that it can hardly be 

 distinguished from the surrounding fluid. This substance can be torn with equal 

 ease in any direction, and no fibrous structure can in any way be detected in it. 

 Under the microscope the mass is quite transparent, and shows no trace of the well- 

 known striation. However, the connective tissue is at this time by no means dis- 

 solved, nor is its texture destroyed. If the potass be removed by acetic acid, and 

 this if it be in excess, by washing, the original texture returns. The author justly 

 remarks, that if the connective tissue consisted of separate fibrils the impossibility of 

 isolating them in the distended condition would be quite inexplicable. It is however 

 intelligible, that in consequence of such an alteration in the connective tissue its 

 cleavability may be diminished or destroyed, which does away with the necessity of 

 supposing a fibrous structure. On the other hand, if a piece of tendon be hardened 

 by a strong solution of caustic potass, or by nitric or hydrochloric acids, no fibres 

 can be demonstrated in it (Bericht, pp. 40, 41). It is easy enough to verify the 

 truth of these statements, by treating a piece of tendinous tissue with acetic acid, 

 when, as is well known, the fihrillated appearance disappears ; then keeping in view 

 one of the distended and transparent " bundles," slowly add a solution of caustic 

 ammonia, the transparent mass will be seen gradually to shrink, and eventually to 

 resume, what appears to be, a most distinctly fibrous appearance. 



The gelatinous or rather gelatiniform areolatetl connective tissue of Professor 



