44 



points of their maxillae, the punctures being visible from the outside as small elongated 

 specks. (Darwin, Miiller.) 



I give these particulars rather in connection with what I said before on Calopogon ; 

 for in the Canadian Orchises the spur is a true nectary ; during the two or three days 

 before the dehiscence of the anther, free nectar is secreted in the spur, until it fills about 

 a third of its total length. 



The flower of Orchis rotundifolia resembles very much that of 0. mascula described 

 by Darwin. The sepals and lateral petals are independent from each other, and the lcbed, 

 white, and spotted lip is nearly horizontal, forming a most convenient stage for its visitors, 

 probably small Andrenidae. 



The flower of the other Canadian species of the genus Orchis, 0. spectabilis, differs in 

 several respects. The five upper parts of the perianth are united, forming over the col- 

 umn a galea not unlike that of many Labiatae, while the ovate lip is entire and smooth ; 

 a more important point of difference is that it hangs down, thus facilitating approach to 

 the Sphingidae or hawk-moths, which are wont to remain poised on the wing while in- 

 serting their proboscides into the nectaries ; and the showy white of the lip, contrasting 

 with the delicate purple of the galea above, joined to the absence of perfume, naturally 

 leads to the inference that the moths are day-flying species. Is not also the nearly 

 straight and cylindrical spur admirably fitted for the slender beak of the ruby-throated 

 humming-bird? However, the nectar is doubtless accessible as well to the larger bees, 

 whose tongues can easily be lengthened as far as the bottom of the spur ; and none of the 

 guests mentioned could in their interested visits avoid contact with the viscid glands 

 that keep watch over the entrance to the nectary. 



Mr. E. Malan in " Science Gossip," 1885, p. 101, says that, in the European 0. mas- 

 cula, "a warm cloudy morning is necessary to enable the pollinia to escape freely, arid 

 indeed, it is only on such a morning that I have ever seen humble-bees visiting the plant." 

 From this may be understood the importance of noting as far as possible not only the 

 dates of observations, but also the hour of the day and state of the weather. 



In our second genus of the Ophrydeae, Habenaria, we have here at last some Cana- 

 dian species of Orchids, of which some insect visitors are well-known, Pollinisation has 

 even been observed repeatedly on one species. Prof. A. Gray, in the Journal of Science 

 and Art, gave in 1862 and 1863 the results of his. careful examination of twelve species 

 in reference to their fertilisation ; in the last edition of his Botanical Text-Book, he 

 names and figures a moth bearing pollen-masses of the largest species, Habenaria orbicu- 

 lata. As Mr. Baldwin gives in his book all the important details from these and other 

 sources, I shall scarcely do more than recall the principal features of each species. 



There are extraordinary differences in the dimensions of the flowers and in the shapes 

 of their organs. The nectary is either sack-shaped, conical, or long and thread-like ; its 

 entrance may be wide open, or contracted, or obstructed by projections of the column or 

 the lip. The upper petals and the sepals are in some species grouped as a roof over the 

 column, in others they are thrown back so as to allow a side approach. In some the lip 

 hangs down in the shape of a strap (latin, habena), in others it projects forward with its 

 end either pointed or spread out into three fan-like and fringed lobes, etc. 



The lip of H. dilatata, though narrower, entire, and slightly curved upwards, seems, 

 as in Orchis rotundifolia, destined to serve as a standing place for insect visitors. No 

 movement of depression or rotation, says Prof. Gray, was detected in the caudicles of the 

 pollinia after their removal from the cells. The stigma being much narrower and situated 

 higher than in Orchis, such a movement is less necessary. The narrowness of the lip 

 naturally increases the chances of the pollinia brought by an insect being directed straight 

 to the stigma in the narrow throat of the flower. 



//. mrescew and II. riridis, var. bracteata, have their flowers disposed so as to oblige 

 insects to approach the spur from the sides. In the former a "nose-shaped protuberance" 

 on the base of the lip divides in two the orifice of the spur. The latter species, the type 

 of which, H. viridis, is found in England, has been described by Darwin, who ,from the 

 presence of a ridge down the hanging lip, and of two nectar secreting spots directly under 

 the rostellum glands, concluded that insects must alight on the right or the left and detach 

 only one pollinium at a time. 



