XI PHENOMENA OF ORGANIC NATURE 403 



training, which is one of the forms of external 

 conditions, converts what are originally only in- 

 structions, teachings, into habits, or, in other 

 words, into organisations, to a great extent ; but 

 this second cause of variation cannot be considered 

 to be by any means a large one. The third cause 

 that I have to mention, however, is a very exten- 

 sive one. It is one that, for want of a better 

 name, has been called " spontaneous variation " ; 

 which means that when we do not know anything 

 about the cause of phenomena, we call it spon- 

 taneous. In the orderly chain of causes and 

 effects in this world, there are very few things of 

 which it can be said with truth that they are 

 spontaneous. Certainly not in these physical 

 matters in these there is nothing of the kind 

 everything depends on previous conditions. But 

 when we cannot trace the cause of phenomena, 

 we call them spontaneous. 



Of these variations, multitudinous as they are, 

 but little is known with perfect accuracy. I will 

 mention to you some two or three cases, because 

 they are very remarkable in themselves, and also 

 because I shall want to use them afterwards. 

 Eeaumur, a famous French naturalist, a great 

 many years ago, in an essay which he wrote upon 

 the art of hatching chickens which was indeed a 

 very curious essay had occasion to speak of 

 variations and monstrosities. One very remark- 

 able case had come under his notice of a variation 



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