224 Insect Architecture. 



and into the meshes of this, by pushing and pressing, it 

 thrust grains of earth, securing them with silk till the whole 

 was rendered opaque; and the further operations of the 

 insect could no longer be watched, except that it was 

 observed to keep in motion, finishing, no doubt, the silken 

 tapestry of the interior of its little chamber. When it was 

 completed, M. Reaumur ascertained that the portion of the 

 structure which had been built under his eye was equally 

 thick and compact with the other, which had been done 

 under ground. 



The grubs of several of the numerous species of may-fly 

 (Ephemera) excavate burrows for themselves in soft earth, on 

 the banks of rivers and canals, under the level of the 

 water, an operation well described by Scopoli, Swammerdam, 

 and Reaumur. The excavations are always proportioned 

 to the size of the inhabitant ; and consequently, when it is 

 young and small, the hole is proportionally small, though, 

 with respect to extent, it is always at least double the 

 length of its body. The hole, being under the level of the 

 river, is always filled with water, so that the grub swims 

 in its native element, and while it is secure from being 

 preyed upon by fishes, it has its own food within easy reach. 

 It feeds, in fact, if we may judge from its egesta, upon the 

 slime or moistened clay with which its hole is lined. 



In the bank of the stream at Lee, in Kent, we had occasion 

 to take up an old willow stump, which, previous to its being 

 driven into the bank, had been perforated in numerous 

 places by the caterpillar of the goat-moth (Cossus ligniperda). 

 From having been driven amongst the moist clay, these 

 perforations became filled with it, and the grubs of the 

 ephemerae found them very suitable for their habitation : for 

 the wood supplied a more secure protection than if their 

 galleries had been excavated in the clay. In these holes of 

 the wood we found several empty, and some in which were 

 full-grown grubs. (J. R.) 



The architecture of the grub of a pretty genus of beetles, 

 known to entomologists by the name of Cincindela, is pecu- 

 liarly interesting. It was first made known by the eminent 



