47 



I have also tried to ascertain which are the natural visitors of our Lady's slippers. 

 In the summer of 1883, I could find in C. pubescens only a dead Buprestis, Authaxia 

 inornata, perhaps overpowered by a yellow spider, that had possession of the lip and had 

 spun some threads in it, The beetle is a well known flower-loving species. This spider 

 is frequently found in the flowers of this lady's slipper, and so must get in them sufficient 

 prey to repay it. On another occasion, I found in a lip an Andrena nivalis, but also dead ; 

 it had very likely been unable to escape from the flower on account of its too large size, 

 for it had no traces of pollen on its thorax and was consequently at its first visit. At 

 last, this summer, Mr. W. H. Harrington captured a live Osmia vicina on the lip of 

 a flower : it had its thorax all besmeared with pollen and must have had a hard struggle 

 to free itself from the gummy anther, for it seemed nearly helpless. 



With C. spectabile, I was a little more fortunate ; I first caught on the 2nd of July 

 1883, a Megackile melanophxa in the lip of a flower. On the 21st of June 1884, I 

 obtained in the same Lady's- Slipper — 



Two bees : Megackile centuncularis, St. Farg ; Antkopkora terminalis, Cress. 



One beetle : Trichius affinis, Gory. 



Three Lepidoptera: Pamphila Cernes, Bd. et. Lee; Pamphila Mystic, Scud- 

 der ; Eudamus Tityrus, -Fabr., \ 



•and also several smaller moths which went freely in and out by the medium opening of 

 the lip. As for the three Lepidoptera named above, which nearly entirely filled up the 

 lip, 1 regret, in my hurry to secure them, not to have tried to see how they would get 

 out; it would most likely have been by the same way that they went in; and, if they 

 touched the pollen at all, rather than remove any, they would only leave on it some of 

 their delicate scales, and thus it does not seem possible that their visits can be of any. use 

 to the plant. 



I was not a little pleased, while watching a plant, to see the Megackile centuncularis 

 fly straight into the lip without alighting : it was evidently well used to the road to the 

 sweets, and immediately passed under the column. I covered the flower with my net, 

 when the bee hurried to come out by a side opening, and as I expected I found the hairs 

 of its thorax matted with pollen old and new. This was also the case with the two other 

 bees. 



The beetle I found lying on its back under the column, busy sucking the nectar-like 

 exudation on the long hairs which line the base of the lip. Replaced in<another flower, 

 it did not hesitate as to what direction it should take; it disappeared under the staminodes 

 and soon came out under one of the anthers, brushing its shoulder against it. When I 

 tried the experiment with a Megackile, the result was precisely the same ; only the bee 

 was much quicker in its movements. If I obstructed the posterior openings, or if the 

 flower was smaller, the insect began at once to bite and tear with its powerful mandibles, 

 till it had made the hole large enough to pass through. I noticed also that when the 

 temperature was low, the bee was not active enough to effect its exit : in a cool room it 

 remained as if powerless. 



On comparing the known guests that are able to fertilise C. pubescens and C. spectabile, 

 we find naturally the larger ones in the latter species, which, has larger flowers and has 

 also no pointed tip to the anther-filament to hold the edge of the lip; it thus allows a 

 larger insect to leave the flower. That tip is also absent in C. acavle, whose flowers are 

 rather larger again, and in the odd little C. arietinum. The two last named species are 

 remarkable for having the median opening of the lip obstructed, the former by folds of its 

 edge closing together, and the other by abundant white hairs, similar to those that thickly 

 line the base of the lip inside. The object is obviously to compel the guests after their 

 feast to go out under the anther, but it must be exceedingly interesting to witness them, 

 when they enter force their way where there seems to bo no way. I do not know that 

 any visitors have been found in these flowers, nor in those of C. parviflorum, which seems 

 to differ from C. pubescens only by its smaller size and brighter colours. On account of the 

 position of the anthers of C. acaule, exactly above the centre of the posterior openings of 

 the lip, the pollen must adhere as a general rule exactly in the middle of the back of the 



