NOTES ON THE FERTILISATION OF OECIIIDS 359 



NOTES ON THE FERTILISATION OF ORCHIDS. 



Br Colonel M. J. Godfery, F.L.S. 



It is comparatively easy to witness the visits of insects to spur- 

 Lcaring orchids such as Orchis morio, mascula, etc., whose nectar is 

 attractive to various bees. With spurless genera secreting no nectar, 

 such as Ophrys and Ceplialanthera, whose visitors may be confined 

 to a single species, it is quite a different matter. One may see 

 hundreds of flowering plants year after year, without once seeing an 

 insect aUght on them. It is useless to watch isolated specimens, and 

 even numbers do not always bring success. Last May 1 watched a 

 colony of 74 spikes of Ophrys litigiosa for long periods on various 

 days, but in vain. Later I found that not a single flower had set a 

 capsule, perhaps owing to a spell of cold weather having delayed the 

 appearance of the necessary insect till too late. The knowledge of 

 such a possibility, after a fruitless vigil, often in the broihng sun, 

 makes a severe strain on the patience. 



Ophrys aeachnitiformis Gren. & Phil. This species, frequent 

 in the neighbourhood of Hyeres, France, is commonly called the Bee 

 Orchid by visitors, though its resemblance to the latter is only super- 

 ficial. On March 14th, 1921, I watched a group of 6 plants for a 

 long time. I caught a bee, settled on a flower of Anemone sielJaia, 

 bearing two pairs of pollinia, evidently those of arachnitiformis, as 

 no other orchid with yellow pollinia was then in flower ; later I took 

 a bee on the wing with three j^airs of pollinia. At intervals the same 

 kind of bee came along, very quick and difficult to follow with the 

 eye, looked at the flowers of the orchid without alighting, and passed 

 on ; two of these had pollinia on their heads, easily visible in flight 

 by their bright yellow colour. Finally, to my great satisfaction, a 

 bee settled on the orchid, but another bee immediately came to the 

 same flower, knocked the first visitor to the ground, where I netted 

 it, but, itself alarmed, flew away. The bee caught had three pairs of 

 pollinia on its head, and was identified by Mr.'Willoughby Gardner, 

 F.E.S., as Andrena Trimmerana S . All the bees seen were of the 

 same kind. On March 17th, 1922, at Les Salins, near Hyeres, I 

 caught 4 bees with pollinia on their heads, visiting arachnitiformis. 

 These were identified at the Paris Museum of Natural History as 

 Colletes cunicularius 6 . Twenty spikes gathered on this occasion 

 proved to have had every flower visited, except the top one in each 

 spike ; in most cases both pollinia had been removed, and there was 

 also pollen on the stigma. No spike had more than four flowers. 

 This i)lant is therefore visited by at least two species of bees, and is 

 extremely well fertilised. It presents a marked contrast to the 

 numerous other species of Ophrys in the south of France, all my 

 efforts to witness the fertilisation of which have so far been in vain. 



Ophrys apifera Huds. In Journ. Bot. 1921, p. 285, I gave 

 reasons for believing that this species is occasionally visited by insects. 

 This year I made special efforts to obtain direct evidence of such 

 visits. On May 8th, at A^ence, near Nice, I found a spike from the 

 lowest flower of which both pollinia had been removed. On May 13th, 



