98 BRAINS OF RATS AND MEN 



the more complex instinctive cycles of mating, etc., 

 and of evidence of intelligent behavior. The ecto- 

 striatum and mesostriatum appear to be responsible 

 for feeding reflexes and the epistriatum for certain 

 visual correlations. Rogers (1922) summarizes his 

 observations in these words: 



After loss of cortex and hyperstrlatum there issues a long 

 period of helplessness, but the bird may regain the ability to 

 feed itself, but does not go through the mating or nesting cycles 

 of behavior. It is shown that the hyperstriatal (hypopallial?) 

 area, without the cortex, can carry out a single association or 

 learning process involving the correlation of several different 

 physiological reactions to form the customary behavior cycle. 



Within the hemispheres there are no excitable 

 cortical areas for skeletal muscles, though the under- 

 lying ectostriatum appears to be excitable — the one 

 demonstrated instance being for movements of the 

 beak as in feeding (Rogers, 1922^). Stimulation of 

 the cortex itself reveals three excitable areas for 

 visceral reactions, involving the peripheral sympa- 

 thetic system (Fig. 18): vasomotor and pinnamotor 

 effects and pupillary constriction of the opposite eye. 

 The vasomotor and pinnamotor effects are probably 

 expressions of a very generalized type of cortical 

 control over thalamic functions. 



The instinctive endowments of birds are very 

 complex and their behavior appears to be highly 

 emotional. Their intelligence, however, is not usually 

 rated very high. When we compare the brains of 

 reptiles, birds, and mammals we see that corpus 



