178 HAECKEL 



return to Jena, in his view. First, he thought, 

 two features of Darwin's system must be given a 

 completely new and original complexion. Firstly, 

 the bottom of the tree, where life begins. Secondly, 

 the crown of all terrestrial evolution : the manner 

 in which man is connected with the tree. It was 

 his philosophic vein that settled both points, the 

 philosophy of unity that sought to replace God by 

 natural development, both below and above, in 

 regard to the primitive cell and in regard to man. 

 But the way in which he set about it was very far 

 removed from all conventional philosophy. The 

 whole rigour of his professional zoology found 

 expression in it. And that was really the novelty 

 of it. The same conclusions might have been 

 drawn by any dozen ordinary philosophers, once 

 they got on the right track. Even they could see 

 that, if two and two are four, one and one are two, 

 and three times three nine. Haeckel went very 

 differently, and much more profoundly, to work. 



As an old pupil of Virchow's he applies the cell- 

 theory to Darwinism in the lower stage. The 

 first living things, the roots of the great tree of 

 life, consisted of a single cell. The logic of the 

 cell-theory itself went as far as this. But is the 

 individual cell the simplest of all living forms ? 

 Here there was a long-standing controversy as to 

 definitions. At first the cell was regarded literally 

 as a kind of chamber, like the cell in the honey- 

 comb. Then it was found that the jelly-like, 

 mobile matter within the cell-chamber was the 

 essential element, the vehicle of life. Finally, it 



