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. 
_ Réaumur, a famous French naturalist, a great 
Beary 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 
’ DD 2 
= 
—— 
