Herrick, Brain of Certain Reptiles. 83 



ened by conduplication. The cellular structure of this body in 

 reptilia is nearer that of the axial lobe than that of the cortex. 

 Fibres pass from this body, at its mouth on the ventro-caudal 

 aspect, into the hippocampus. From the ventricular aspect 

 (ental aspect of the cells) a strong bundle of large dark fibres 

 passes to the precommissure. A part of these fibres do not en- 

 ter the commissure but pass at once to the thalamus. These 

 fibres the writer has compared to a separated tract from the for- 

 nix which took a more direct route than the rest whose position 

 was described as like that in mammals. We find similar fibres 

 in fishes and think it is a mistake to compare them to any part 

 of the fornix. Edinger is probably in error in thinking these 

 fibres (f' Fig. 4, Plate VII,) the bundles from the habena, for 

 the latter, if our observations are correct, pass to the lateral as- 

 pect of the brain base and arch caudo-dorsad upon the convex- 

 ity of the caudo-lateral cortex (parietal lobe ?) or connect with 

 the radix lateralis. The fornix fibres appear at /"in the same 

 figure. 



Inasmuch as the spheroidal structure which is so conspicu- 

 ous in serpents is not developed in all reptiles- even, it seems to 

 us that the term nucleus sphaericus can hardly be adopted as 

 a general term, but may be restricted to that organ where de- 

 veloped, while the occipito-basal lobe may include the whole re- 

 gion however developed. In the snake it would include more 

 than the sphaericus. 



The Histology of the Cortex. 



In conformity with our determination to postpone a discus- 

 sion of the literature to a later period in this series, we only 

 consider the recent papers which have a direct bearing upon the 

 topics in hand. 



Dr. Adolf Meyer has contributed an extended paper^ upon 

 the fore brain which covers much the ground of our own previ- 

 ous work in a thorough and painstaking manner. Although he 

 has unwittingly repeated many of our own observations they 

 are none the less welcome. 



^Zeitsch. f. 'cviss. Zoo I., LV, I. 



