-HEREDITARY VARIATION 71 



of training ; all the world knows that exercise has a great 

 effect in this way ; we always expect to find the arm of a 

 blacksmith hard and wiry, and possessing a large develop- 

 ment of the brachial muscles. No doubt, training, which 

 is one of the forms of external conditions, converts what 

 are originally only instructions, teachings, into habits, or, 

 in other words, into organizations, 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 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 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. Reaumur, 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 mon- 

 strosities. One very remarkable 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 spontaneous 

 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 very carefully at the 

 time. It frequently happens that a variation occurs, but 

 the persons who notice it do not take any care in noting 

 down the particulars, until at length, when inquiries come 

 to be made, the exact circumstances are forgotten ; and 

 hence, multitudinous as may be such " spontaneous " varia- 

 tions, it is exceedingly difficult to get at the origin of them. 



