230 HAECKEL 



as regarded the question of the embryo. But there 

 was another, a man far away in South America, 

 that increased it — Fritz Miiller. 



Born in 1822, one of the finest pioneers in zoo- 

 logical work, Fritz Miiller had wished to become a 

 higher teacher, but had abandoned his plan on 

 account of the oath that had to be taken by every 

 servant of the State. In 1849 he wrote to the 

 Ministry requesting that he might be allowed to 

 dispense with the formula '^ So help me God, 

 through Jesus Christ." Meeting with a refusal, he 

 went to South America, and began a solitary life as 

 a student in the primitive forest, and sought to accu- 

 mulate valuable zoological material. Darwin called 

 him ^* the king of observers." In 1864 he published 

 an essay of ninety-four pages with the title For 

 Darwin. He revived and improved the old idea 

 of Oken's, and made fresh contributions to the 

 natural history of the Crustacea that were literally 

 stupefying. We may say that the point that he 

 believed he had established, in virtue of the law, in 

 regard to the genealogical tree of the Crustacea, 

 was afterwards, with apparent justice, called into 

 question, even by supporters of the law such as 

 Arnold Lang. That, however, did not diminish 

 the extent of his influence at the time. Haeckel 

 has generously acknowledged how strongly he felt 

 that influence himself. Nevertheless all that has 

 been said about Haeckel's priority in fully applying 

 and shaping the law, and in its final formulation, 

 is perfectly correct. 



When Haeckel had massed his material he had 



