256 THE BEGINNINGS OF LIFE. 



know of the process of crystallization, we ought not 

 only to be more easily convinced as to the possibility 

 of the evolution of even specific organisms out of so- 

 lutions containing organic matter, we might even have 

 been prepared for the occurrence of all that marvellous 

 interchangeability of diverse organic forms which we 

 actually do encounter. 



But let us take another illustration, showing that 

 even biological phenomena with which we are quite 

 familiar and which we are bound to accept, are never- 

 theless quite incapable of being understood. 



We are perfectly familiar with the fact that the 

 ovum of every animal tends to go through a uniform 

 series of changes, and at last to give birth to the 

 same kind of animal as that from which it was itself 

 derived. But if, at the same time, we could place 

 under the microscope a human ovum and others, at 

 a similar early stage, of a monkey, a pig, and a sprat, 

 how slight would be the differences presented. The 

 kind of structure is perfectly similar in each case. 

 Each has been formed as a free organic element, and 

 though they may differ from one another only a little 

 in point of size, yet how different are the ultimate 

 products! The seemingly similar masses of granules 

 are endowed with the most diverse potentialities from 

 the changes ensuing in one a reasoning man may be 

 produced, whilst from those in another a man-like ape, 

 a grovelling mammal, or an insignificant fish may 

 appear. And yet such changes are nothing but the 



