NERVOUS SYSTEM. VERTEBRATA. 131 



characteristic of this breed. The entire brain is much 

 lengthened. The cerebrum is pushed strongly forward and 

 upward to occupy the cavity of the cranial protuberance, 

 and is separated from the somewhat depressed cerebellum 

 bya waist-like constricted region consisting of the thalam- 

 encephalon and mesencephalon. The distortion of the brain 

 in this breed does not seem to entail any noticeable change 

 in habits or intelligence. 



This specimen also shows well the structure of the optic 

 chiasma. Upon its section surface a number of stripes are 

 visible, successively dark and light. This appearance is 

 due to the cut edges of a series of band -like bundles of 

 nerve-fibres derived alternately from either optic nerve. 



0. C. 1321 E. 

 Presented by W. B. Tegetmeier, Esq. 



Tegetmeier, Proc. Zool. Soc. 1856, p. 366. 



D. 162. The brain of a Bustard (Otis sp.). The specimen, 

 although in a bad state of preservation, shows the general 

 form of the brain. 



The cerebral hemispheres are remarkably short and broad 

 and almost globular in contour. They leave most of the 

 thalamencephalon exposed and cover no part of the optic 

 lobes. (This may be due partly to artificial displacement.) 



The tectal commissure is overhung posteriorly for about 

 one-third of its extent by the anterior lobe of the cere- 

 bellum. In front it is separated by a transverse groove 

 the infolded posterior commissure from the thalamen- 

 cephalon. The roof of the third ventricle has been removed 

 exposing its slit-like cavity bordered by the prominent optic 

 thalami. Between the postero-median margins of the 

 cerebral hemispheres lies the epiphysis. Its stalk originates 

 from the thalamencephalon roof in front of the optic 

 thalami. 0. C. 1321 B. 



D. 163. The brain of a Wattled Crane (Grus carunculatus). The 

 cerebral hemispheres are strongly arched above, flat below, 

 and from the dorsal aspect have an almost quadrangular 

 outline. Their anterior ends are rounded and give attach- 

 ment to the olfactory bulbs on their ventral surface. The 



K2 



