1881 WOEK ON ECHINODEEMS 117 



its prey only slightly, and thus to give its larvae fresh 

 meat instead of old dry meat. Though Fabre insists 

 so strongly on the unvarying character of instinct, 

 yet it shows that there is some variability, as on 

 pp. 176, 177. 



I fear that I shall have utterly wearied you with 

 my scribbling and bad handwriting. 

 My dear Eomanes, 



Yours very sincerely, 



CH. DAKWIN. 



From G. J. Eomanes to C. Darwin, Esq. 



18 Cornwall Terrace, Kegent's Park, N.W. : April 17, 1881. 



Your long letter has been most refreshing to me 

 in every way. 



I am looking forward with keen interest to the 

 appearance of your book on Worms, and am unex- 

 pectedly glad to hear that my letter was of any use. 



I should very much like to see the book you 

 mention, and from what you say about sending 

 it I shall not order it. But there is no need to send 

 it soon, as I have already an accumulation of books 

 to review for ' Nature.' 



I am very glad that you think well of the Echino- 

 derm work. Several other experiments have occurred 

 to me to try, and I hope to be able to do so next 

 autumn, as also the interesting experiment suggested 

 by Frank of rotating by clockwork (as you did the 

 plants) an Echinus inverted upon its aboral pole, to 

 see whether it would right itself when the influence 

 of gravity is removed. 



