3l8 BOTANY [CHAP. X 



Letter 641 filaments, remember Dr. C. says that the unopened flowers 

 habitually set fruit. I think that you will change your views 

 on the imperfect flowers of Viola and Oxalis. . . . 



Letter 642 To J. Scott. 



May 2nd [1863]. 



I have left home for a fortnight to see if I can, with little 

 hope, improve my health. The parcel of orchid pods, which 

 you have so kindly sent me, has followed me. I am sure 

 you will forgive the liberty which I take in returning you the 

 postage stamps. I never heard of such a scheme as that you 

 were compelled to practise to fertilise the Gongora 1 ! It is 

 a most curious problem what plan Nature follows in this 

 genus and Acropera? Some day I will try and estimate 

 how many seeds there are in Gongora. I suppose and hope 

 you have kept notes on all your observations on orchids, for, 

 with my broken health and many other subjects, I do not 

 know whether I shall ever have time to publish again ; 

 though I have a large collection of notes and facts ready. 

 I think you show your wisdom in not wishing to publish too 

 soon ; a young author who publishes every trifle gets, some- 

 times unjustly, to be disregarded. I do not pretend to be 

 much of a judge ; but I can conscientiously say that I have 

 never written one word to you on the merit of your letters that 

 I do not fully believe in. Please remember that I should very 

 much wish for a copy of your paper on sterility of individual 



1 See Fertilisation of Orchids, Ed. II., p. 169. " Mr. Scott tried 

 repeatedly, but in vain, to force the pollen-masses into the stigma of 

 Gongora atro-pttrpurea and trtmcata ; but he readily fertilised them by 

 cutting off the clinandrum and placing pollen-masses on the now exposed 

 stigma." 



2 In the Fertilisatio?i of Orchids, Ed. II., p. 169, Darwin speculates 

 as to the possible fertilisation of Acropera by an insect with pollen- 

 masses adhering to the extremity of its abdomen. It would appear that 

 this guess (which does not occur in the first edition) was made before 

 he heard of Criiger's observation on the allied genus Gongora, which is 

 visited by a bee with a long tongue, which projects, when not in use, 

 beyond and above the tip of the abdomen. Criiger believes that this 

 tongue is the pollinating agent. Criiger's account is in the Journal of 

 the Linn. Soc., VIII., 1865, p. 130. 



