286 THE JOURNAL 01'- BOTAXY 



to be more numerous than that of purely insect-pollinated indi- 

 viduals, of which every unvisited flower sets no capsule at all. 



Darwin pointed out that even now, in 0. apifera, the large viscid 

 disc attaches itself to any object brushing against the rostellum, and 

 that the pollinia can thus be removed, sometimes even after they have 

 become attached to the stigma. Further, that the caudicles go 

 through the usual movement of depression till they assume the exact 

 position for touching the stigma of another flower (Fert. Orch. ed. 2, 

 p. 56). In other words, the mechanism is still in working order — 

 O. apifera has not lost the capability of being cross-pollinated by 

 insects. That this actually does occur, even at the present day, is 

 proved by the fact that undoubted hybrids have been found growing 

 wild between 0. apifera on the one hand and O. arachnites, 

 O. aranifera, and O. scolopax respectively on the other. These 

 hybrids could not possibly have arisen without the effectual visit of 

 the same insect to each of the parents concerned. For one such 

 visit to two different species of Ophrys in succession, there must be 

 many more in which the insect confines itself to one species only, 

 which is normally the case with bees. 



Organs which are not used tend to become atrophied. Sapro- 

 phytes like Orobanche, Neottia, and Limodorum, which derive 

 nourishment from decaying organic matter instead of from the air, 

 lose their leaves. Petals rendered supei'fluous by the conspicuousness 

 of the anthers disappear, as in Thalictrum and in certain Australian 

 myrtles. Stamens no longer needed vanish altogether, or leave only 

 rudiments behind, as in Ophrys, which can now show only one stamen 

 out of the original six. Nature will not waste nutriment and energy 

 in maintaining functionless organs. That the mechanism of O. api- 

 fera remains to this day in efficient working order is sufficient proof 

 that it has been all along in more or less active exercise of its 

 functions. Darwin himself admitted that it is remarkable that none 

 of the parts in cpuestion show any tendency to abortion (/. e. p. 58). 

 Nor does O. apifera show any signs of deterioration in robustness of 

 growth or brilliance of flower. At Vence its vigour is extraordinary— 

 the plants often nearly 2 ft. tall, and the sepals of a particularly 

 pleasing bright salmon-pink, which I have not seen elsewhere. 

 Either it still enjoys a considerable measure of cross-pollination, or 

 Darwin's theory of the great inferiority of self-fertilisation is much 

 exaggerated. 



M. Pouyanne has made the interesting discovery (Journ. Soc. nat. 

 d'Hortic. de France, Feb., March, 1916) that Ophrys speculum in 

 Algeria is fertilised by the males of Colpa aurea, which appear some 

 time before the females (whose bodies are covered with long red 

 hairs), and engage in ceaseless quest of the latter over ground where 

 they lie buried in the pupa-state, pouncing eagerly on any individual 

 which emerges. He tells me in a letter that if one takes a bunch of 

 O. speculum in the hand to a colony of pupae, the males at once 

 alight on the flowers, and are so engrossed that they pay no attention 

 to the observer. It is easy to see that they make no attempt to 

 suck nectar, but mistake the lip of the flower for a female Colpa, 

 which it resembles sufficiently to deceive the insect, owing to the 



