132 PHYSIOLOGICAL SERIES. 



dorsal farrows are well marked and bound a pair of strong 

 median prominences. They meet in the mid-line behind the 

 anterior border of the hemispheres. The hinder parts of 

 the brain call for no remark. 0. C. 1321 B b. 



D. 164. Brain of a Stone-Curlew (CEdicnemus listriatus). The 

 bad condition of this specimen has apparently led to a 

 certain amount of distortion (e. g. the large interval between 

 the hemispheres and optic lobes is probably unnatural). 

 The hemispheres are markedly globular with well-defined 

 pseudo-temporal lobes. 0. C. 1321 B a. 



D. 165. The brain and spinal cord of a Goose (Anser ferns) at 

 alx)ut the twelfth day of incubation. At this stage the 

 brain shows much resemblance in its hinder parts to that 

 of an adult Lizard, and in its hemispheres to that of an Am- 

 phibian or low Shark, e. g. Notidanus. The optic lobes are 

 large, and occupy a dorsal position immediately in front of 

 the cerebellum. The latter is as yet remarkably small, as 

 in adult Amphibia or Reptilia. The medulla is strongly 

 flexed, and the rhomboid fossa is lengthened and widely 

 open in front, as in Urodeles. The thalamencephalon forms 

 a distinct segment between the optic lobes and the elon^;it< -.1 

 hemispheres. 0. C. 1319. Hunterian. 



D. 166. Median sagittal section of the brain of a Goose (Anser 

 ferus). In this section the brain-cavities are shown. In 

 front, the spacious third ventricle communicating by the 

 foramen of Monro with the ventricle of the right lienii- 

 -pliere and prolonged ventrally behind the optic chiasma 

 into the infundibulum. The anterior wall of this ventricle 

 (lamina terminalis) gives passage to the double anterior 

 commissure. Note the protuberant optic thalami in the 

 upper part of the ventricle and the cut edge of the del i eat. 

 t-la choroidea. 



Posteriorly the third ventricle is connected with the 

 fourth by a narrow pa. a^e, the aqueduct of Sylvius, roofed 

 over by the posterior and tectal commissures, and prolonged 

 laterally to form the cavity of the optic lobes. In this 



