1862 1S71] rOHN TT 307 



own pollen. A remarkable discovery by Hildebrand, 1 namely, that in 



main- on bids the ovules are not developed unless the stigma is pene- 

 trated by the pollen-tubes . . . expla state of the ovarium in 

 A > /•<■>■>. as observed by me." In regard to this subject see Letter 608, 

 p. 280. 



12th, 1 

 I thank you most sincerely for your kindness in writing Lettei 

 to mc-, and for [your] very interesting letti r. Your fact has 

 surprised me greatly, and has alarmed me not a little, for if 1 

 am in error about Acropera I ma}- be in error about Catasetum. 

 Yet when I call to mind the state of the placentae in A. luteola, 

 I am astonished that they should produce ovules. You will 

 see in my book that I state that I did not look at the 

 ovarium of A. Loddigesii. Would you have the kindness to 

 send me word which end of the ovarium is meant by apex 

 (that nearest the flower ?), for I must try and get this species 

 from Kew and look at its ovarium. I shall be extremely 

 curious to hear whether the fruit, which is now maturing, 

 produces a large number of good and plump seed ; perhaps 

 you may have seen the ripe capsules of other Vandeae, and 

 may be able to form some conjecture what it ought to 

 produce. In the young, unfertilised ovaria of many Vandeae 

 there seemed an infinitude of ovules. In desperation it 

 occurs to me as just possible, as almost everything in nature 

 goes by gradation, that a properly male flower might occa- 

 sionally produce a few seeds, in the same manner as female 

 plants sometimes produce a little pollen. All your remarks 

 seem to mc excellent and very interesting, and I again thank 

 you for your kindness in writing to mc. I am pleased to 

 observe that my description of the structure of Acropera 

 seems to agree pretty well with what you have observed. 

 Docs it not strike you as very difficult to understand how 

 insects remove the pollinia and carry them to the stigmas ? 

 Your suggestion that the mouth of the stigmatic cavity may 

 become charged with viscid matter and thus secure the 

 pollinia, and that the pollen-tubes may then protrude, seems 

 very ingenious and new to me; but it would be v< 

 anomalous in orchids, i.e. as far as I have seen. Xo doubt, 

 however, though 1 tried my best, I shall be proved wrong in 

 many points. Botany is a new subject to me. With respect 



1 Bot. Zeitung) [863 and 1865. 



