26 



HOW PLANTS EMPLOY INSECTS TO WORK FOR THEM, 



Fig. 13. Flower of Arethiua, entire, 

 lengtliwise. 



Fig. 11. A sectioii 



hanging shelf, which is stigma, and bo sticky that any pollen it may chance to 

 have brought would be left adhering there. As the head slips by, it must next 



hit the front edge or visor of the hel- 

 met-shaped anther, raise it on its hinge, 

 and so allow one or more of the four 

 loose pellets of pollen to drop out, or 

 be brushed out by the insect's head, to 

 which some of the pollen would stick. 

 When the next flower is entered noth- 

 ing is accomplished ; but on departing, 

 as before, any pollen on its head would 

 be applied to the sticky shelf of stigma 

 overhead, the lid then uplifted, and a 

 fresh charge of pollen taken from this 

 flower to be given to the next, and 

 so on in succession. 



53. It is not unlikely 

 that the pellets of pol- 

 len, as they fall out of the uplifted anther of Arethusa, may some- 

 times miss the insect's head, or fail to adhere to it, and so be lost. 

 But this plan, or something like it, serves the purpose in the por- 

 tion of the Orchis Family of which Arethusa is the representative. 

 In others of that family the result is made surer by considerably 

 different, more economical, and wonderfully curious arrangements, 

 — such especially as those 



54. In Orchises and other plants of that particular tribe of the ^fu,VknthSd 

 Orchis Family. There is only one true Orchis in this country, and l^'^^J^^^^^i 

 that not common, except northward. And its arrangement for fer- posiUoii- 

 tilization is not quite so readily understood as in those Orchises which are named 

 by botanists Habenaria, of which we have many species. Some of these are plen- 

 tiful, such as the Fringe Orchises, either the purple, white, or yellow species. 

 The Greater Green Orchis is not so common, but is taken for the present illustra- 

 tion on account of the size of its blossoms. A reduced figure of it, with its two 

 large round leaves spreading on the ground, and its spike of flowers rising be- 

 tween them on a naked stalk, is m the foreground of the vignette title, and a 

 single blossom, of only twice the size of life, is represented in Fig. 16. 



