Trans. N. V. Ac. Sci. 



81 



Nov. 21, 



the cell-doctrine, which at the time of its establishment was a great ad- 

 vance in biological science ; so the further study of canilage has sup- 

 plied the basis for a generalization, which is a further development, and 

 must take the place of the cell-doctrine. This is Heitzmann's doctrine 

 of living matter, or, as I have named it, the bzopiasson-docirine. 



When the term " cell " was introduced in 1838 and 1839, by Schleiden 

 and Schwann, it was believed that, on ultmiate morphological analysis, 

 every plant and every animal would be found to consist of a number of 

 minute vesicles or sacs, enclosing liquid contents in w^hich is suspended 

 a more solid body, the nucleus. For fully twenty years this idea has 

 been known to be erroneous. In fact, Goodsir, ntarXy forty years ago — 

 only a few years, that is, after Schwann had established the cell-doctrine 

 and attributed the vital power to the cell-membrane, I say, nearly forty 

 years ago Goodsir had experimentally determined that the seat of the 

 vital process of secretion is not in the vesicle as such, but in the so- 

 called cell contents; Naegeli, in 1845, and Alexander Braun, in 1851, 

 had also shown the cell-wall to be comparatively unimportant ; and in 



ll,th;:;:frjiy; 



Figure 3. — Thyroid Cartilage of Adult. Horizontal Section x 600. 



C. Cartilage corpuscle. F. Fibrous portion of cartilage. G. Granules of living matter. 



Fig. 3 shows granules of various sizes in the basis-substince. with lower power of the 

 microscope, which granules are seen with higher powers to be connected with the network 

 of Ifving matter, as shown by Fig. 4. 



