152 Journal of Comparative Neurology. 



pearance and showed a faint yet distinct protoplasmic covering. 

 They averaged about .03 mm. in diameter, the nucleus being ,02 

 mm. In the cytoplasm were a number of thin streaked mass- 

 es of colored material quite unlike, however, the typical chro- 

 mophilic granules. What these "cells" are, I am somewhat 

 at a loss to determine. Throughout their distribution, they re- 

 main dorsal and extend slightly laterad being mingled with 

 cells of the regular spinal type. In no cases were any of these 

 cells around the central canal. 



The cells of the hypophysis are similar to the regular type; 

 like free nuclei. 



Just before reaching the epiphysis there is a sinking in of 

 the cerebral mass, the above mentioned "cells" have practi- 

 cally disappeared, and there was noted the gradual appearance 

 of a dorsal group of large cells in the median line ; these vary 

 from .008 to .010 mm. 



These do not appear to coalesce with the elliptical epen- 

 dyma cells which average 17-22 micra in length by 10-16 micra 

 in diameter. At this level the cells around the ventricle are 

 from 8 to 10 rows deep and of the regular spherical free nuclei 

 type, although at rare intervals some cells are seen in which the 

 cytoplasm has responded to the stain, but no granules were 

 found. The cells of the hemispheres were all around the ven- 

 tricle and were all of the conventional type as were also the 

 cells of the rhinencephalon. 



At the time of the final revision the article of Guisseppe 

 Levi, " Ricerche citologiche comparate sulla cellula nervosa dei 

 vertebrati," Rivista di patologia nervosa e mentale, 1897, 5., is 

 received and some of his results were deemed of importance for 

 the present communication. Among Amphibia the author 

 studied Rana and Bufo of the Anura, Triton cristatus, Spelerpes 

 fuscus and Proteus auguinus of the Urodeles ; these latter are 

 of more interest from the present point of comparison. 



The cells of the ventral columns of the cord have an oval 

 form, the cytoplasm in Spelerpes forming a delicate border 

 about the nucleus. In the Triton this is more distinct and con- 

 tains chromophilic granules which were sharply cut, sometimes 



