THE "GENERAL MORPHOLOGY" 177 



Darwinian question gave him a negative impulse 

 to the study. He thought it would be best to 

 deal with one family of the medusas after another 

 in separate monographs, as time permitted. The 

 first of these essays appeared in 1864 and 1865, 

 and dealt with what are known as the " snouted- 

 medusae " (geryonida). The first volume of the 

 complete work was not published until fourteen 

 years afterwards. If Haeckel had decided to work 

 as a specialist he would have had material enough 

 here to occupy him fully throughout the whole 

 of the sixties, and even longer. The keen student 

 of the radiolaria would be succeeded by the equally 

 keen student of the medusas. More folio volumes 

 would have accumulated, with beautiful plates, 

 such as only the technical student of zoology ever 

 takes out of the library. His name, like that of 

 his friend Gegenbaur almost, would never have 

 reached the crowd. 



It was the influence of Darwin that prevented 

 this. His attention was turned in another direction, 

 and we begin to realise the full greatness of his 

 power when we remember that he nevertheless 

 continued with unfailing quality to publish such 

 detailed studies as those on the medusae. 



Darwinian ideas were fermenting intensely in 

 his mind at that time. The most audacious prac- 

 tical and theoretical problems arose from the 

 fundamental theory, and forced themselves on him 

 at every moment. A great deal was sketched in 

 outline in the Stettin speech, but the serious 

 scientific work would have to be begun on his 



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