26 OUR NATIVE ORCHIDS 



contact with the pollen, which is of course the desideratum 

 here embodied, and which has reference to a tongue corre- 

 sponding to the length of the nectary. There are many 

 of these smaller sphinxes. Let us suppose one to be hovering 

 at the blossom's throat. Its slender capillary tongue enters 

 the opening. Ere it can reach the sweets the insect's head 

 must be forced well into the throat of the blossom, where 

 we now observe a most remarkable special provision, the 

 space between the two pollen discs being exactly adjusted 

 to the diameter of the insect's head. What follows this 

 entrance of the moth is plainly evident. As the insect 

 sips, the sticky discs are brought in contact with the moth's 

 eyes, to which they adhere, and by which they are with- 

 drawn from their pouches as the moth departs. At this 

 time they are in the upright position, but in a few seconds 

 bend determinedly downward and slightly toward each 

 other. This change takes place as the moth is flitting from 

 flower to flower. When the moth with its tongue enters the 

 nectary of a subsequent blossom, by the new position of the 

 pollen clubs they are forced directly against the stigma. 

 This surface is viscid, and as the insect leaves the blossom 

 retains the grains in contact, which in turn withdraw others 

 from the mass by means of the cobwebby threads by which 

 the pollen grains are continuously attached. Thus after 

 the moth's visit the stigma is covered with pollen and the 

 flower cross fertilised. 



" In eff'ecting the cross fertilisation of one of the younger 

 flowers its eyes are again brought in contact with this second 



