AT THE UNIVERSITY 77 



put it together. It was an histological study of 

 the tissues of crabs, and therefore lay in the 

 province of the articulates, an animal group, it is 

 curious to note, which he has not entered into 

 more fully in the course of his long and varied 

 work as special investigator. At Nice he made a 

 thorough study of the nerve-tubes of the spiny 

 lobster and other available marine Crustacea, 

 and discovered several remarkable new structural 

 features in them. At Berlin he entered upon 

 a minute microscopic study of the common craw- 

 fish. His dissertation for the doctorate embodied 

 the main results of his research. It was entitled 

 De telis quibusdam Astaci fluviatilis, and was 

 printed in March, 1857. It appeared the same 

 year in an enlarged form in Miiller's Archiv, 

 with the title The Tissues of the Craw-fish. 

 On March 7th he received his medical degree, 

 Ehrenberg, the great authority on the infusoria, 

 presiding. In the customary way the young doctor 

 had to announce and defend several theses. One 

 of them is rather amusing in view of later events. 



He most vigorously contested the possibility of 

 " spontaneous generation." The meaning of the 

 phrase is that somewhere or at some time a living 

 thing, animal or plant, has arisen, not in the form 

 of a seed or germ or sprout from a parent living 

 thing, but as a direct development out of dead, 

 inorganic matter. Haeckel had not made a 

 personal study of the subject. What he said in 

 his thesis was merely a faithful repetition of 

 Miiller's opinion. At that time it was believed 



