THE MUSEUM HIS HEADQUARTERS 47 



produced themselves by division, threw off sexual off- 

 spring; this was suspected to be a case of so-called 

 alternate generations. Agassiz was able to complete the 

 cycle by tracing the growth of the original unsexual 

 parent stock from the eggs of the second generation. 

 During these investigations he discovered that certain 

 species, which had hitherto been considered distinct, 

 were in reality the male and female of the second gener- 

 ation. 



The first publication in the memoirs of the Museum 

 was a study of the Ophiurans by Theodore Lyman. The 

 second was a catalogue of North American Acalephae 

 by Agassiz, published in 1865. This volume was illus- 

 trated with three hundred and sixty figures drawn from 

 life by his own hand. It is one of the longest and most 

 important of his early publications, and contains many 

 descriptions of jelly-fish first discovered by him both on 

 the Atlantic and the Pacific. As a tribute to his zeal and 

 efficiency as a collector and investigator, it may be men- 

 tioned that many of the Medusae, which he collected on 

 the New England coast fifty years ago, have not been 

 recorded since. 



Agassiz, among other things, showed at this period 

 that Cape Cod was the dividing line for many species of 

 the marine animals frequenting the coast of the North 

 Atlantic, and he also did much work on Echini, in 

 preparation of his " Revision," published several years 

 later. Most of the work of these earlier years was so 

 fundamental in character that it is freely quoted, con- 

 sciously or unconsciously, in all modern text-books of 

 zoology. 



It will be remembered that Darwin's " Origin of 

 Species " appeared in 1859. Although Agassiz never 



