278 FERTILISATION [l868. 



To see penetration of pollen-tubes is not difficult, but in 

 most cases requires some practice with dissecting under a 

 one-tenth of an inch focal distance single lens ; and just at 

 first this will seem to you extremely difficult. 



What a capital observer you are a first-rate Naturalist 

 has been sacrificed, or partly sacrificed, to Public life. 

 Believe me, yours very sincerely, 



CH. DARWIN. 



P.S. If you come across any large Salvia, look at it the 

 contrivance is admirable. It went to my heart to tell a man 

 who came here a few weeks ago with splendid drawings and 

 MS. on Salvia, that the work had been all done in Germany.* 



[The following extract is from a letter, November 26th, 1868, 

 to Sir Thomas Farrer, written as I learn from him, " in answer 

 to a request for some advice as to the best modes of ob- 

 servation." 



" In my opinion the best plan is to go on working and 

 making copious notes, without much thought of publication, 

 and then if the results turn out striking publish them. It 

 is my impression, but I do not feel sure that I am right, 

 that the best and most novel plan would be, instead of de- 

 scribing the means of fertilisation in particular plants, to 

 investigate the part which certain structures play with all 

 plants or throughout certain orders ; for instance, the brush 

 of hairs on the style, or the diadelphous condition of the 

 stamens in the Leguminosas, or the hairs within the corolla, 

 &c. &c. Looking to your note, I think that this is perhaps 

 the plan which you suggest. 



It is well to remember that Naturalists value observations 



* Dr. W. Ogle, the observer of gratefully to his relationship with 



the fertilisation of Salvia here my father in the introduction to 



alluded to, published his results in his translation of Kerner's ' Flowers 



the 'Pop. Science Review,' 1869. and their Unbidden Guests.' 

 He refers both gracefully and 



