COSMIC PHILOSOPHY 



dogs, are manifested without education by their 

 descendants. Indeed it is familiar to breeders 

 that the dispositions and instincts of domestic 

 animals can be to a certain extent modified by 

 training and selection, no less than their physical 

 constitutions.^ 



The physical explanation of the automatic co- 

 hesion of psychical states implied in hereditary 

 instinct is not difficult at this stage of our in- 

 quiry. When the experience of many past gen- 

 erations has uniformly contributed to establish a 

 certain arrangement of transit lines in the chief 

 ganglia of the animal, there must be a hereditary 

 tendency for such transit lines to develop by the 

 mere process of nutrition. And where the psy- 

 chical life is very simple, and but little varied 

 from generation to generation, a nervous system 



^ ** How strongly these domestic instincts, habits, and dis- 

 positions are inherited, and how curiously they become min- 

 gled, is well shown when different breeds of dogs are crossed. 

 Thus it is known that a cross with a bulldog has affected for 

 many generations the courage and obstinacy of greyhounds ; 

 and a cross with a greyhound has given to a whole family of 

 shepherd dogs a tendency to hunt hares. These domestic in- 

 stincts, when thus tested by crossing, resemble natural instincts, 

 which in a like manner become curiously blended together, 

 and for a long period exhibit traces of the instincts of either 

 parent : for example, Le Roy describes a dog whose great- 

 grandfather was a wolf, and this dog showed a trace of its wild 

 parentage only in one way, by not coming in a straight Hne 

 to his master, when called. ' * Darwin, Origin of Species y 6th 

 edition, p. 210. 



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