586 HOMES WITHOUT HANDS. 



construction has been mentioned as applied to separate cells of 

 certain hymenoptera, and that no explanation has been given 

 of the mode by which the six-sided cells are made. It is always 

 easier to explode previous theories than to supplant them with 

 one that really explains the enigma ; and such is certainly the 

 case with these cells. But when we come to examine the group 

 of nests which are made by an insect called Apoica pallida, the 

 subject takes a wider range, and we are even more hopelessly 

 bewildered than before. In the nests already mentioned the 

 cells are hexagonal, but in these specimens the entire nests 

 assume a form more or less hexagonal, as may be seen by 

 reference to the ^lustration. 



In order to prevent misunderstanding, I must here remark, 

 that the seven nests or cell-groups were not all found adhering 

 to a single branch, as seems to be the case, but that they have 

 been placed near each other in such a manner as to allow of 

 easy comparison, and to show their peculiar form. The large 

 mushroom-shaped nest in the centre, and the small cell-group 

 which occupies the extremity of the bough, appear as they were 

 formed by the insects, but the others have only been arranged 

 for the convenience of comparison. 



Even their position has been necessarily altered. Nests of 

 this kind are always placed with the mouths of the cells down- 

 ward ; but, as their peculiar form could not easily be seen if they 

 were allowed to retain their natural position, some of them 

 have been set on their edges, so as to exhibit their outline to 

 the spectator. This is notably the case with that nest which 

 occupies the left hand of the illustration, and which is the most 

 striking of aU the specimens. 



If the reader wJU refer to the illustration, he will see that 

 the nests are by no means uniform in size or shape. The larger 

 one, for example, which occupies the centre, rather exceeds ten 

 inches in diameter, while the small nest at the end of the 

 same branch is scarcely half as wide, and the others are of 

 all the intermediate sizes. In shape, too, they differ, some being 

 perfectly hexagonal, others partly so, while others again are 

 nearly circular, though on a careful inspection they show faint 

 traces of the hexagonal form. 



We will now examine these nests, and see where they agree 

 with and differ from each other. 



