224 TRUE TALES OF THE INSECTS. 



the wing-form, species of this sub-family may be easily 

 recognized. Often their size is extraordinary, for 

 members of Cocytius, a South American genus, which 

 includes the largest known Sphingidse, expand as much 

 as eight and nine inches across the wings. The length 

 of their tongue calls for similar remark, and some repre- 

 sent the extreme of development in this direction (see 

 Fig. 41). A tongue five or six inches long is nowise 

 uncommon ; that of a tropical African attains to seven 

 and a half inches ; the proboscis of Cocytius chientitis 

 reaches nearly two inches more ! and Dr. Wallace some 

 years ago predicted with confidence the discovery of a 

 Sphinx in Madagascar with a tongue even of eleven or 

 twelve inches, which could reach the nectar in the largest 

 flowers oi AngrcEcuni sesqiiipcdalc, a singular Madagascar 

 orchid, whose immensely deep nectaries vary in length 

 from ten to fourteen inches. At the other end of the 

 scale are forms like Ellcina harrisii oi the United States, 

 where the organ is obsolete, or a mere membraneous 

 rudiment. Another distinguishing feature of a large 

 number of species in this group consists in their ten- 

 dency to spinose, or armed tibiae and tarsi, which in the 

 Choerocampince is barely indicated in Deilephila. 



These insects, as well as the sub-family Smerinthinse, 

 pupate in the earth without silk, an event more dangerous 

 to the individual than in the cocoon-making groups, 

 for the roving larvce, seeking shelter, may find the 



