346 I. IKE AT DOWN. yETAT. 33-4$. 



courage and stomach do not fail, for the Brit. Assoc. (Do 

 you not consider it your duty to be there ?) And why cannot 

 you come here afterwards and work ? . . . . 



THE MONOGRAPH OF THE CIRRIPEDIA, 

 October 1846 to October 1854. 



[Writing to Sir J. D. Hooker in 1845, m y father says : " I 

 hope this next summer to finish my South American Geology, 

 then to get out a little Zoology, and hurrah for my species 

 work. . ." This passage serves to show that he had at this 

 time no intention of making an exhaustive study of the 

 Cirripedes. Indeed it would seem that his original intention 

 was, as I learn from Sir J. D. Hooker, merely to work out one 

 special problem. This is quite in keeping with the following 

 passage in the Autobiography : " When on the coast of Chile, 

 I found a most curious form, which burrowed into the shells 

 of Concholepas, and which differed so much from all other 

 Cirripedes that I had to form a new sub-order for its sole 

 reception. . . . To understand the structure of my new 

 Cirripede I had to examine and dissect many of the com- 

 mon forms ; and this gradually led me on to take up the 

 whole group." In later years he seems to have felt some 

 doubt as to the value of these eight years of work, for 

 instance when he wrote in his Autobiography " My work 

 was of considerable use to me, when I had to discuss in the 

 ' Origin of Species ' the principles of a natural classification. 

 Nevertheless I doubt whether the work was worth the con- 

 sumption of so much time." Yet I learn from Sir J. D. 

 Hooker that he certainly recognised at the time its value to 

 himself as systematic training. Sir Joseph writes to me : 

 41 Your father recognised three stages in his career as a 

 biologist : the mere collector at Cambridge ; the collector and 

 observer in the Beagle, and for some years afterwards ; and 

 the trained naturalist after, and only after the Cirripede 



