STRUCTUEE OF CELLS. 581 



the hive bee. No matter how large may be the nest of an 

 Icaria, or how full of cells it may be, the cells are all so alike in 

 shape and size that they must apparently be the cradles of 

 insects belonging to the same sex. 



This fact is curiously brought out in a remarkable series of 

 cell-groups which have been placed on a single leaf, some of 

 which are shown in the lower part of the illustration. The leaf 

 is rather long, and, being dry, is now curved by its own force. 

 This leaf seems to have possessed some fascination for the Icarias, 

 as upon the upper surface no less than fifteen nests have been 

 established, none of great length, and all nearly or quite com- 

 pleted. In none are the cells perfectly straight, all having a 

 slight curve downwards on account of the delicate material of 

 which they are made. 



The insect which builds these curious cells is a commonplace- 

 looking creature, of a soft, greyish-brown colour, with a mode- 

 rately large head and a little rounded abdomen, not very unlike 

 the Gynips Kollari, which has already been described. It is a 

 native of India, and the nests which have been mentioned were 

 sent from Bareilly. 



There is also a nest made by an allied insect belonging to the 

 genus Sphex, and coming, as far as is known, from the same 

 locality. As in the preceding case, the habitation is placed in 

 the hollow of a leaf, which has either curled in the process of 

 withering, or has been bent by the insect and retained in its 

 cylindrical form by silken threads. On inspecting the nest it 

 is seen to consist of a mass of delicate threads that are not 

 unlike those of the common silkworm, which cross and recross 

 each other so as to fiU up the hollow of the leaf, and to form a 

 receptacle for the future young. 



The insect is a large one, being a full inch in length, and of 

 rather a formidable appearance. In colour it is black, with the 

 exception of a few narrow transverse streaks of bright yellow 

 upon the fore part of the thorax, and the abdomen is placed at 

 the end of a long footstalk. 



In connection with this branch of the subject, I must call the 

 attention of the reader to the curious cell-group of Polistes 

 aterrima, a figure of which is given on page 461. 



