HEREDITARY TRANSMISSION AND VARIATION. 93 



have to mention, however, is a very extensive 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 spontaneous. 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 mat- 

 ters, — in these there is nothing of the kind, — every- 

 thing 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. Keaumur, 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 re- 

 markable case had come under his notice of a variation 

 in the form of a human member, in the person of a 

 Maltese, of the name of Gratio Kelleia, who was born 

 with six fingers upon each hand, and the like number 

 of toes to each of his feet. That was a case of spon- 

 taneous variation. Nobody knows why he was born 

 with that number of fingers and toes, and as we don't 

 know, we call it a case of "spontaneous" variation. 

 There is another remarkable case also. I select these, 

 because they happen to have been observed and noted 



