PREHISTORIC SCIENCE 



cate, had become, through his conception of fishes, 

 birds, and hairy animals as separate classes, a scientific 

 zoologist of relatively high attainments. 



In the practical field of medical knowledge, a certain 

 stage of development must have been reached at a very 

 early day. Even animals pick and choose among the 

 vegetables about them, and at times seek out certain 

 herbs quite different from their ordinary food, prac- 

 tising a sort of instinctive therapeutics. The cat's 

 fondness for catnip is a case in point. The most primi- 

 tive man, then, must have inherited a racial or instinc- 

 tive knowledge of the medicinal effects of certain herbs ; 

 in particular he must have had such elementary knowl- 

 edge of toxicology as would enable him to avoid eating 

 certain poisonous berries. Perhaps, indeed, we are 

 placing the effect before the cause to some extent ; for, 

 after all, the animal system possesses marvellous pow- 

 ers of adaption, and there is perhaps hardly any poison- 

 ous vegetable which man might not have learned to 

 eat without deleterious effect, provided the experi- 

 ment were made gradually. To a certain extent, then, 

 the observed poisonous effects of numerous plants 

 upon the human system are to be explained by the 

 fact that our ancestors have avoided this particular 

 vegetable. Certain fruits and berries might have come 

 to have been a part of man's diet, had they grown in 

 the regions he inhabited at an early day, which now 

 are poisonous to his system. This thought, however, 

 carries us too far afield. For practical purposes, it suf- 

 fices that certain roots, leaves, and fruits possess prin- 

 ciples that are poisonous to the human system, and 

 that unless man had learned in some, way to avoid 



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