THE PIGEON 4i? 



vein usually known as the epigastric takes blood from the 

 great omentum, or sheet of fat which covers the abdominal 

 viscera, to the left hepatic vein. It represents the anterior 

 abdominal vein of the frog. 



The cerebral hemispheres of the brain are large, smooth, 



and rounded. The roof of the lateral ventricles 

 Nervous ; s thin. The olfactory lobes are very small. 



sense Organs. The cerebellum and cerebrum meet over the 



thalamencephalon, thrusting the optic lobes to 

 the sides, where they project as two round, hollow masses. 

 The cerebellum is ridged transversely. There are twelve 

 cranial nerves, corresponding to those of the rabbit (p. 455). 

 The sense of smell is not well developed. Hearing is acute, 

 the labyrinth possessing the organ known as the cochlea 

 which was quite rudimentary in the frog. Sight is very 

 keen, and the eye is remarkable for the presence of a 

 Vascular pigmented organ, known as the pecten, which 

 protrudes into the vitreous humour from the " blind 

 spot " where the optic nerve enters. 



