22 SCIENCE FROM AN EASY CHAIR 



the ingenious supposition illustrated by the imaginary 

 history of the giraffe, and to declare that this was the law 

 of Nature and is actually going on every day, without, so 

 to speak, getting out of his chair. He never attempted to 

 show by observation or experiment that such a change of 

 form as the stretching of the neck by straining after food 

 could and did occur, or that if it did that it could be 

 transmitted by a parent or couple of parents to their 

 offspring. And consequently for many years no one 

 attached much value to Lamarck's notions on the subject. 

 When, fifty years later, Darwin's very different theory 

 became widely received, based on the demonstrable fact 

 that congenital variations (not stretchings and warpings 

 acquired in the lifetime of a parent, but variations which 

 are inborn, and occur in some but not other individuals 

 living under one and the same set of conditions) are trans- 

 mitted to offspring, and that those among these variations 

 which are favourable to success in life will enable their 

 possessor to survive and to produce young inheriting those 

 favourable variations then it occurred to 'those naturalists 

 who were inclined to believe in Lamarck's suggestion to 

 inquire into the solid facts in regard to that also, and to 

 see whether his bare statement was true. From that day 

 to this, it has never been shown that it is true. It is, 

 indeed, to begin with, a rare thing to find instances of 

 either wild animals or wild plants which, growing up in 

 unusual conditions, have their structure altered and 

 " adapted " so as to be more serviceable in those unusual 

 conditions than their usual structure would be; and in 

 those cases where such adaptive alterations have been 

 produced, every experimenter is agreed in stating that 

 he has found that when (even after several generations in 

 the changed conditions) the young are restored to their 

 original conditions, they simply grow up into the original 

 forms : no permanent change in the stock or race has 



