THE KOVE BEETLE. 615 



la order to enable them to perform the various movements which are 

 necessary for their aquatic existence, their hind legs are developed into 

 oars with flattened blades and stiff hairy friuges, and the mode of res- 

 piration is slightly altered in order to accommodate itself to the sur- 

 rounding conditions. It has already been mentioned that in all insects 

 the respiration is conducted through a series of apertures set along the 

 sides, and technically called spiracles. In the Water Beetles the spira- 

 cles are set rather high, so as to be covered by the hollowed elytra, and 

 to be capable of breathing the air under those organs. When, there- 

 fore, the beetle dives it is in no ways distressed for want of air, as it 

 carries a tolerable supply beneath the elytra. When, however, that 

 supply is exhausted, the beetle rises to the surface, just pushes the ends 

 of the elytra out of the water, takes in a fresh supply of air, and again 

 seeks its subaquatic haunts. 



The male of the Great Water Beetle, in common with other species, 

 is specially notable for the singular development of the fore legs, the 

 tarsi of which are developed in a most extraordinary apparatus caused 

 by the dilatation of the three first joints, which are flattened so as to 

 form a nearly circular disc, covered on its under surface with a multi- 

 tude of wonderfully-constructed suckers, one being very large, another 

 about half its size, and the others very small and set on pear-shaped 

 footstalks. 



Passing by several large and interesting families, we come to the cu- 

 rious creatures which will at once be recognized by reference to the il- 

 lustration on page 616. These beetles are popularly known by the 

 name of Rove Beetles, or Cocktails, the latter name being given to 

 them on account of their habit of curling up the abdomen when they 

 are alarmed or irritated. The common Black Cocktail has so diabol- 

 ical an aspect when it assumes this attitude, standing its ground de- 

 fiantly with open jaws and elevated tail, that the rustics generally call 

 it the Devil's Coach-horse. It has, moreover, the power of throwing 

 out a most disgusting odor, which is penetrating and persistent to a 

 degree, refusing to be driven off even with many washings. 



These beetles are termed Staphylinidse, or Brachelytra, the latter 

 term signifying " short elytra," and being a very apposite name, as the 

 elytra are short, square, and not more than one-fourth tlie length of 

 the abdomen. If we watch one of these beetles settling after its flight, 

 we shall see the object of its flexible tail. The wings are so large and 

 the elytra so small that the process of folding the delicate membranes 

 could not be completed without some external aid. When the insect 

 alights it suddenly furls its wings into loose folds, and then, by means 

 of its tail, it pushes the wings under the elytra, which are then shut 

 down. This process, although rather elaborate, is effected in a very 

 rapid manner. . 



