ICARIAS. 



595 



Icariaa. 



its mouth downward, and at first making it comparatively short. 

 When the cell has nearly attained its due length, a second is 

 placed alongside the first, and a third is added in like manner, 

 each being lengthened as required. As the cells at the base of 

 the series are finished first, it is evident that they gradually di- 

 minish toward the end, those at the extremity being often not one 

 quarter so long as those at the base. 



The material employed in making these cells is woody fibre, 

 like that which is used by our common British wasps, and the 

 color is rather dark yellowish-brown, so that, in spite of the curi- 

 ous method in which the nest-groups project from the branches, 

 they are not seen so readily as might be imagined from their ec- 

 centric form. 



In these, as in many other forms of cells made by hymenopter- 

 o'us insects, is to be found an enigma which as yet is unsolved, 

 and for the mention of which I am indebted to Mr. P. Smith, of 

 the British Museum : all the cells are of equal size. 



Now this point, which would not particularly strike an ordi- 

 nary observer, is of the greatest importance to those who have 

 studied the economy of insects, and have bestowed much thought 

 upon them. If we examine the nest of a hive-bee, and take any 

 single comb, we shall find that the cells are extremely variable in 

 size — the latgest being those which are occupied by the future 



