22 PSYCIIOLOGT. 



Exposure to ret;iliation, to other enemies, to traps, to 

 poisons, to the dangers of repletion, must be regular 

 parts of his existence. His lack of all thought by which to 

 Aveigh the danger against the attractiveness of the bait, and 

 of all volition to remain hungry a little Avhile longer, 

 is the direct measure of his lowness in the mental scale. 

 And those fishes which, like our cunners and sculpins, 

 are no sooner thrown back from the hook into the water, 

 than they automatically seize the hook again, would soon 

 expiate the degradation of their intelligence by the extinc- 

 tion of their type, did not their exaggerated fecundity atone 

 for their imprudence. Appetite and the acts it prompts 

 have consequently become in all higher vertebrates func- 

 tions of the cerebrum. They disappear when the physiol- 

 ogist's knife nas left the subordinate centres alone in place. 

 The brainless pigeon will starve though left on a corn- 

 heap. 



Take again the sexual function. In birds this devolves 

 exclusively upon the hemispheres. When these are shorn 

 away the pigeon pays no attention to the billings and coo- 

 ings of its mate. And Goltz found that a bitch in heat 

 would excite no emotion in male dogs who had suffered 

 large loss of cerebral tissue. Those who have read Dar- 

 win's ' Descent of Man' know Avhat immense importance in 

 the amelioration of the breed in birds this author ascribes 

 to the mere fact of sexual selection. The sexual act is not 

 performed until every condition of circumstance and senti- 

 ment is fulfilled, until time, place, and partner all are fit. 

 But in frogs and toads this passion devolves on the lower 

 centres. They show consequently a machine-like obe- 

 dience to the present incitement of sense, and an almost 

 total exclusion of the power of choice. Copuiation occurs 

 per fas aid nefas, occasionally between males, often with 

 dead females, in puddles exposed on the highway, and 

 the male may be cut in two without letting go his hold. 

 Every spring an immense sacrifice of batrachian life takes 

 place from these causes alone. 



No one need be told how dependent all human social 

 elevation is upon the prevalence of chastity. Hardly any 

 factor measures more than this the difference between civili' 



