tSsg LETTER TO LEUCKART 



175 



velopment as the criterion of morphological views — first, from 

 the study of the Hydrozoa during a long voyage, and secondly, 

 from the writings of Von Bar. I have done my best, both by 

 precept and practice, to inaugurate better methods and a better 

 spirit than had long prevailed. Others have taken the same 

 views, and I confidently hope that a new epoch for zoology is 

 dawning among us. I do not claim for myself any great share 

 in the good work, but I have not flinched when there was any- 

 thing to be done. 



Under these circumstances you will imagine that it was very 

 pleasant to find on your side a recognition of what I was about. 



I sent you, through the booksellers, some time ago a copy of 

 my memoir on Aphis. I find from INIoleschott's Untcrsuchungen 

 that you must have been working at this subject contemporane- 

 ously with myself, and it was very satisfactory to find so close 

 a concordance in essentials between our results. Your memoirs 

 are extremely interesting, and to some extent anticipated results 

 at which my friend, Mr. Lubbock* (a very competent worker, 

 with whose paper on Daphnia you are doubtless acquainted), had 

 arrived. 



I should be verv glad to know what you think of my views 

 of the composition of the articulate head. 



I have been greatly interested also in your Memoir on 

 Pentastomum. There can be no difficulty about getting a notice 

 of it in our journals, and, indeed, I will see to it myself. Pray 

 do me the favour to let me know whenever I can serve you in 

 this or other ways. 



I shall do mvself the pleasure of forwarding to you immedi- 

 ately, through the booksellers, a lecture of mine on the Theory 

 of the Vertebrate Skull, which is just published, and also a little 

 paper on the development of the tail in fishes. 



I am sorry to say that I have but little time for working at 

 these matters now, as my position at the School of Mines obliges 

 me to confine myself more and more to Paleontology. 



However, I keep to the anatomical side of that sort of work, 

 and so, now and then, I hope to emerge from amidst the fossils 

 with a bit of recent anatomy. 



Just at present, by the way, I am giving my disposable hours 

 to the completion of a monograph on the Calycophoridas and 

 Physophoridse observed during my voyage. The book ought to 

 have been published eight years ago. But for three years I could 



* The present Sir John Lubbock, M.P. 



