THE DRAWING OF THE SEINE. 173 



why they are built; and determine also whether or not 

 this crayfish burrows from the nearest open water to 

 the point inland where the chimney is erected, or does 

 it travel overland to a convenient spot and burrow 

 downwards? I believe I have knowledge of upward 

 burrowing and the subsequent building of the chimney. 



Bared fingers must not be thrust too carelessly into 

 the mass of myriophyllum and lily stems. There are 

 insignificant aquatic insects sure to be tangled there, 

 that can bite as sharply as they can swim swiftly ; and 

 when, by chance, a half-dozen nip at your finger-ends at 

 once, your ejaculations may startle your own self. It is 

 remarkable how much emphasis rolls, ready- waiting, 

 under the tongues of bug-bitten mortals. 



The most numerous of the aquatic insects brought up 

 by the net, and which have bitten me severely more 

 than once, are everywhere known as water-boatmen, or 

 Kotonectae, a much prettier name. Let us give them a 

 moment's consideration. They are perfect insects, and 

 not larval forms of some aerial creature ; and are strictly 

 aquatic forms. Still, they have wings, and if they find 

 their home pond drying up, will take a prolonged flight 

 in search of more comfortable quarters. A curious feat- 

 ure of their habits is, that they always swim on their 

 backs, just as we saw that the little spring-time crusta- 

 cean, Branchipus, does; and it is only when swimming 

 that they may be said to be at home. They never know 

 when to stop. They come to the surface witli a series 

 of most sprightly jerks, tarry a moment, and dive grace- 

 fully to the bottom, then up again; and so they con- 



