504 THE WRITING OF THE 'ORIGIN OF SPECIES.' [1859. 



tant characters for main divisions are Embryological ? The 

 seed itself cannot be considered as such, I suppose, nor the 

 albumens, Szc. But I suppose the Cotyledons and their posi- 

 tion, and the position of the plumule and the radicle, and the 

 position and form of the whole embryo in the seed are 

 embryological, and how far are these very important ? I wish 

 to instance plants as a case of high importance of embryo- 

 logical characters in classification. In the Animal Kingdom 

 there is, of course, no doubt of this. 



C. Darwin to J. D. Hooker. 



Down, March 5th [1859]. 



My dear Hooker, — Many thanks about the seed . . . 

 it is curious. Petrels at St. Kilda apparently being fed by 

 seeds raised in the West Indies. It should be noted whether 

 it is a nut ever imported into England. I am very glad you 

 will read my Geographical MS. ; it is now copying, and it will 

 (I presume) take ten days or so in being finished ; it shall be 

 sent as soon as done. . . . 



I shall be very glad to see your embryological ideas on 

 plants ; by the sentence which I sent you, you will see that 

 I only want one sentence; if facts are at all, as I suppose, 

 and I shall see this from your note, for sending which very 

 many thanks. 



I have been so poorly, the last three days, that I sometimes 

 doubt whether I shall ever get my little volume done, though 

 so nearly completed. . . . 



C. Darwin to J. D. Hooker. 



Down, March 15th [1859]. 

 My dear Hooker, — I am pleased dit what you say of my 

 chapter. You have not attacked it nearly so much as I 

 feared you would. You do not seem to have detected 7nany 

 errors. It was nearly all written from memory, and hence I 

 was particularly fearful ; it would have been better if the 



