XI PHENOMENA OF ORGANIC NATURE 397 



some experimentalists have carefully examined the 

 lower orders of animals, among them the Abbe 

 Spallanzani, who made a number of experiments 

 upon snails and salamanders, and have found 

 that they might mutilate them to an incredible 

 extent ; that you might cut off the jaw or the 

 greater part of the head, or the leg or the tail, and 

 repeat the experiment several times, perhaps cut- 

 ting off the same member again and again ; and 

 yet each of those types would be reproduced 

 according to the primitive type : Nature making 

 no mistake, never putting on a fresh kind of leg, 

 or head, or tail, but always tending to repeat and 

 to return to the primitive type. 



It is the same in sexual reproduction : it is a 

 matter of perfectly common experience, that the 

 tendency on the part of the offspring always is, 

 speaking broadly, to reproduce the form of the 

 parents. The proverb has it that the thistle does 

 not bring forth grapes ; so, among ourselves, there 

 is always a likeness, more or less marked and dis- 

 tinct, between children and their parents. That is 

 a matter of familiar and ordinary observation. We 

 notice the same thing occurring in the cases of the 

 domestic animals dogs, for instance, and their 

 offspring. In all these cases of propagation and 

 perpetuation, there seems to be a tendency in the 

 offspring to take the characters of the parental 

 organisms. To that tendency a special name is given 

 and as I may very often use it, I will write it 



