106 



tenison, is carved, and held in a position by a delicate mem- 

 brane. Insects liffht on the lower lip of the flower. In front 

 of this lip are two processes known as antennae. In Cata- 

 setum saccatum only one arm is sensitive; in some species 

 both are sensitive. When the insect touches the left hand 

 one, the excitement is conveyed along it, the membrane re 

 taining the pollinium is ruptured, the latter released and 

 thrown with considerable force with the viscid disc foremost, 

 and in such a direction as to come in contact with the head of 

 the insect. When the insect visits another plant containing 

 the pistil it leaves some of the pollen on the stigma. 



The Angraecum sesquipedale is a native of Madagas- 

 car. The spur in this species is longer than of any other orchid. 

 It varies from 10 to over 14 inches in length. It is said, ac- 

 cording to Darwin, than an insect must have a tongue 11 to 

 12 inches long in order to reach the nectar. 



Darwin, in the following words, says: "It is, however, 

 surprising that any insect should be able to reach the nectar. 

 Our English Sphinxes have proboscides as long as their 

 bodies; but in Madagascar their must be moths with probo- 

 scides capable of extension to a length of between 10 and 11 

 inches. This belief of mine has been ridiculed by some ento- 

 mologists, but we now know from Fritz Mueller that there is 

 a sphinx-moth in South Brazil which has a procoscis of nearly 

 suiKcient length, for when dried it was between ten and 

 eleven inches long. When not protruded it is coiled up into 

 a spiral of at least twenty windings-" 



Mr. Forbes has found a moth in Madagascar with a 

 tongue Tong enough to reach the nectar. 



A green, whip-like nectary hangs down beneath the la- 

 bellum. According to Darwin only the lower one and one- 

 half inches, in the species he examined, as filled with nectar. 



