180 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



flowers or is very sceptical on the subject ; later they report 

 that they have found instances of the operation being effected by 

 insects ; and ultimately they either believe in the subject as set 

 forth by Darwin, or have little to say against it. So far as the 

 good seed which takes the responsibility of reproducing the plant 

 is concerned, I think there is little doubt that nature arranges 

 for the fertilisation to be effected by insects, though in many 

 cases the alternative of self-fertilisation is provided, but in such 

 a manner as to be available only as a last resort. 



Observers in the tropics are generally led to disbelieve in the 

 agency of insects by the large number of seed-capsules which 

 they see in some situations, which even in their early stages 

 never furnished an instance of an insect employed in fertilising 

 them (or rather of an insect effecting the operation while seeking 

 its own sustenance) or of any sign of one having visited the 

 flowers. I am convinced that a very large proportion of the 

 seed-capsules of this kind have not resulted from fertilisation at 

 all, but that they are capsules formed in consequence of irritation 

 of the stigmatic surface by dust, or some other sabstance, and in 

 a similar manner to what I have often produced on home-grow- 

 ing plants many years ago. I had what 1 consider remarkable 

 proof in support of my contention from Mr. F. C. Lehmann 

 when speaking with him on the subject last year. Mr. Lehmann 

 remarked that, considering the great number of flowers produced 

 by any species of Orchids over a given area, the number of seed- 

 vessels generally speaking was very small, but that in very 

 exposed situations, such as on isolated wind-swept hills, it was 

 very common to find a quantity of plants in the bleakest spot 

 covered with capsules, while in sheltered situations the same 

 species would give but few fruits. I have no doubt that in these 

 occasional instances the capsules are invariably produced by 

 dust or grit being carried to the stigmatic disc, and that they 

 contained no good seeds ; but Mr. Lehmann promises to test the 

 matter, and we may hope for further information on the subject. 

 I think it very probable that what are known as bad varieties or 

 a bad strain of any species of Orchid coming from a particular 

 locality may have originated at some remote period from dearth 

 of insects to effect fertilisation, and consequent resort being had 

 to the alternative of self-fertilisation the progeny of which 

 degenerate ; or from the degeneracy of the subjects so heavily 



