1862— 1871] JOHN SCOTT 315 



that iuch recorded cases must be due to unnatural conditions Letter 639 

 of life ; and think I said so in the ( Origin? I am not sure tl. I 

 I understand your result, [nor] whether it means what I have 

 above obscurely expressed. If you can prove the above, do 



publish ; but if you will not publish I earnestly beg you to let 

 me have the facts in detail ; but you ought to publish, for I 

 may not use the facts for years. I have been much interested 

 by what you say on the rostellum exciting pollen to protrude 

 tubes ; but are you sure that the rostellum does excite them ? 

 Would not tubes protrude if placed on parts of column or 

 base of petals, etc., near to the stigma ? Please look at the 

 Cotta, dener* (or Journal of Horticulture) to be published 



to-morrow week for letter of mine, in which I venture to 

 quote you, and in which you will see a curious fact about 

 unopened orchid flowers setting seed in West Indies. Dr. 

 Crliger attributes protrusion of tubes to ants carrying stig- 

 matic secretion to pollen 3 ; but this is mere hypothesis. 

 Remember, pollen-tubes protrude within anther in Neottia 

 nidus-avis. I did think it possible or probable that perfect 

 fertilisation might have been effected through rostellum. 

 What a curious case your Gongora must be : could you spare 

 me one of the largest capsules? I want to estimate the 

 number of seed, and try my hand if I can make them grow. 



where the phenomenon is fully discussed, Scott's observations {Trans. B 

 Soc. E</i/i„ 1863) are given as the earliest, except for one case recorded 

 by Lecoq (F/condation, 1862). Interesting work was afterwards done 

 by Hildebrand and Fritz Miiller, as illustrated in many of the letters 

 addressed to the latter. 



' See 1 f Species, Ed. 1.. p. 251. for Herbert's observations on 



self-impotence in Hippeastrum. In spite of the uniformness of the 

 results obtained in many successive years, Darwin inferred that the 

 plants must have been in an "unnatural state." 



■Journal of Horticulture and ( dener, March 31st, 1S63. 



A short note describing Outer's discovery of self-fertilisation in ( 

 Epidendrum, etc., and referring to the work of " an excellent observer, 

 Mr. J. Scott.'' Darwin adds that he is convinced that he has underrated 

 the power of tropical orchids occasionally to produce seeds without the 

 aid of insects. 



^ s In Criiger's paper {Litm 'our;:., VIII., 1865 ; read March 3rd 



1864) he speaks of the pollen-masses in situ being acted on by the 

 stigmatic secretion, but no mention is made of th< y of ants. He 



describes the pollen-tubes descending " from the [pollen] masses still 

 in situ down into the ovarian canal." 



