ON CIRRIPEDES. 37 



the ' Origin of Species ' the principles of a natural 

 classification." Sir Joseph Hooker remembers that 

 Darwin at an earlier time "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 work" 

 (Letter to F. Darwin). 



Professor Huxley considers that just as by Darwin's 

 practical experience of physical geography, geology, 

 etc., on the Beagle, "he knew of his own knowledge 

 the way in which the raw materials of these branches 

 of science are acquired, and was, therefore, a most 

 competent judge of the speculative strain they would 

 bear," so his Cirripede work fitted him for his sub- 

 sequent speculations upon the deepest biological 

 problems. " It was a piece of critical self-discipline, 

 the effect of which manifested itself in everything 

 your father wrote afterwards, and saved him from 

 endless errors of detail" (Letter to F. Darwin, "Life 

 and Letters"). The history of Darwin's career has 

 often been used as an argument against those who, 

 not having passed through a similar training as 

 regards systematic zoological work, have ventured 

 to concern themselves with the problems of evolution. 

 Professor Meldola has recently treated of this subject 

 in his interesting presidential address to the Entomo- 

 logical Society (1896). He says : 



" It used formerly to be asserted that he only is worthy of 

 attention who has done systematic, i.e. taxonomic, work. I 



