CONNECTIVE TISSUE. 217 



possibility seems to me, to-day, to be very slight, so much so 

 that even a direct transformation of hyaline into fibrous carti- 

 lage is doubtful. I am positive that one variety of basis-substance, 

 one kind of connective tissue, can never be transformed into another 

 except through the intermediate stage of medullary tissue. A com- 

 pletely developed tissue must first return to the embryonal condition, 

 before a new and different tissue can develop from it. 



Remak * was the first to approach our present views respect- 

 ing the formation of basis-substance of cartilage. He maintained 

 that it is deposited between the outer and the inner membrane of 

 the cartilage-cell, whereupon the outer membrane perishes, and 

 the shells of the " parietal substance " fuse together in order to 

 form the intercellular substance. 



E. Briicke, t in accordance with the views held by Max 

 Schultze, considered the outermost layer of the cartilage cells, 

 destitute of a membrane, to be the former of basis-substance 

 proper. The layer close around the unchanged portion of the 

 cell-body he asserts to be more dense than the rest of the basis- 

 substance, and this condensation causes the appearance of a 

 capsule. Similar views are held by E. HeidenhainJ concerning 

 the formation of single and stratified capsules. If these views 

 were correct in every respect, we ought to find in developing 

 cartilage enormous corpuscles, corresponding in size with the 

 whole territory, before the changes at their periphery had 

 ensued. But the facts are just the contrary to this, for in the 

 embryonal cartilage the corpuscles are decidedly smaller than in 

 that of the adult. 



A. Spina demonstrates that, in fully developed cartilage, 

 with advancing age the amount of basis-substance increases at 

 the expense of the cartilage corpuscles. These become pale, 

 finely granular, destitute of nuclei, and then disappear in the 

 basis-substance. The protoplasmic reticulum of the cells, he 

 says, does not perish, but remains, somewhat altered in its 

 character, in the basis-substance. This explains why, in the 

 articular cartilage of the very aged, the corpuscles are so 

 extremely scanty and small. 



* Miiller's Archiv, 1852. 



t " Die Elementarorganismen." Sitzungsber. d. Wiener Akademie d. 

 Wissensch., 1861. 



t Studien des Physiol. Instit, zu Breslau, 1863. 



' ' Untersuchungen iiber die Bildung der Knorpelgrundsubstanz." 

 Sitzungsber. d. Wiener Akademie d. Wissensch., 1880. 



