RAFT OF EGGS OF THE GNAT. 75 



filled with water, even though exposed. To put this 

 to the test, 1 placed half a dozen of these boats upon 

 the surface of a tumbler half-full of water : I then 

 poured upon them a stream of that element from the 

 mouth of a quart bottle held a foot above them. Yet 

 after this treatment, which was so rough as actually 

 to project one out of the glass, I found them floating 

 as before upon their bottoms, and not a drop of water 

 within their cavity *." We have repeatedly pushed 

 them to the bottom of a glass of water, but they 

 always came up Immediately to the surface appa- 

 rently un wetted. 





Magnified view of the boat of gnats' eggs. 



"We have contented ourselves with giving here 

 only a few examples of the maternal care which is 

 displayed by insects in depositing their eggs, though 

 we could have filled the volume with similar details. 

 The instincts which are thus displayed are of the 

 most interesting description ; and they cannot fail to 

 impress the most careless observer with a deep reve- 

 : rence of that providential wisdom by which they are 

 implanted in these small and feeble creatures for the 

 maintenance of their race. But it is not essential, in 

 order to produce this reverence, to exaggerate the cir- 

 cumstances under which these remarkable peculiarities 

 are displayed. The infallibility of the instinct of in 

 sects in such cases is, in most books of natural his- 

 tory, maintained to be without exception. " Led by 

 an instinct," say Kirby and Spence, " far more un- 

 • Introd. iii, p. 32 



f2 



