i88i. 



33 



Trans. N. Y. Ac. Set. 



various stages of existence ! These investigations are illustrated by the 

 accompanying drawings. 



Doubt as to the interpretation is impossible : instead of being a 

 mass of basis-substance in which a number of cartilage corpuscles are 

 imbedded, hyaline cartilage is a filigree of living matter, in the meshes 

 of which a number of blocks of basis-substance are imbedded. 



Now, for our subject proper. 



The founder of the cell-doctrine, Schwann, has recorded in the in- 

 troduction to his great work, published in 1839, that the doctrine was 

 based to a large extent upon investigation of the constitution of carti- 



FiGURE 2. — Thyroid Cartilage of Adult, kept in strong Alcohol. Horizontal Section x i2oo. 



C. Shrivelled cartilage corpuscle. i R. Reticulum in basis-substance. 



O. Longitudinal off-shoots. I G. Granules of living matter. 



Fig. 2 shows offshoots from the cartilage corpuscles and the network in the basis-substance, 

 with more or less large granules interwoven, as it were, in the network. 



lage. After Johannes Miiller had described cartilage-corpuscles that 

 were hollow, and Gurlt had spoken of some as vesicles, — when Schwann 

 had succeeded, as he thought, "in actually observing the proper wall 

 of the cartilage corpuscles, first in the branchial cartilages of the frog's 

 larvae and subsequently also in the fish," he was led by these and 

 other researches to conjecture "that the cellular formation might be a 

 widely extended, perhaps a universal, principle for the formation of 

 organic substances." And just as the study of cartilages has led to 



