Herrick, Morpholo^ of Brain of Bony Fishes. 35 



regions of the tuber. A cluster of distinct polyhedral cells lies 

 laterad of these tracts near the surface in all fishes examined. 



In Carpiodes the lateral recesses of the tuber, forming the 

 mammillaria in a restricted sense, are large and double and the 

 bodies lie cephalad of the spur-like caudal lobe of the hypoaria. 

 Dorsad of the decussatio hypophysis a lateral spur of the ventriclus 

 infundibuli forms a projection into the latter from the region of 

 which, as well as from ihe caudo lateral regions of the tuber, the 

 fibres of the tract from the tuber to the ventral commissure 

 arise. 



In larvae of Salamander just removed from the uterus the 

 hypophysis, which is closely attached to the greatly- prolonged 

 infundibulum, consists of amedio-caudal portion already distinctly 

 follicular, and a bifid cephalic portion which is extended laterally 

 some distance. Only the first mentioned median portion is 

 directly connected with the infundibulum, which latter consists 

 is this region of a single layer of the epithelium. In the adult 

 fhe two portions are not easily distinguished in our sections. 

 Tiie majority of the mass being composed of follicular tubules 

 and blood vessels. 



Here we have the same distinctions and there is also a more 

 or less evident saccate modification of the infundibulum in the 

 region of the attachment of the hypophysis which corresponds 

 probably with the saccate lobe of the latter in fishes. 



In the the case of Menopoma there is a well defined saccus 

 vasculosus lying caudo-dorsad of the hypophysis and here the 

 relations seem entirely similar to those above described in fishes. 

 The whole lateral surface of the infundibulum is covered with a 

 dense net work of capillaries and at the point of union with the 

 saccus the latter force their way inward, not entering the ventricle 

 but pushing the epithelium inward as the whole wall spreads 

 outward. The result is a plexiform sac as above described. 

 The connection with the anterior part of the hypophysis is more 

 direct than in fishes. 

 IV. — The inieroptic commissives 



The various bundles of transverse fibres immediately adja- 

 c-ent to the chiasm always prove difficult to distinguish. In 

 higher vertebrates these commissures have been so variously de- 

 scribed and the same commissure has so often received different 



