70 VIEWS OF THE MICROSCOPIC WORLD. 



mine. The insect possesses the form depicted in figure 10 7, which presents a 

 magnified view of its under side. The head (a), is of a yellow color, and on each 

 side of it are placed two reticulated eyes (b 6), of a deep crimson hue. This crea- 

 ture has three pairs of feet, fringed with hair ; the first of which often escape 

 observation from their color and position. The second pair are generally thrown 

 forward in a swimming position, as displayed in the figure. The hinder pair are 

 the strongest, and are armed at their extremities with claws. The beak is hard 

 and pointed, and in some of the larger species is capable of inflicting a severe 

 Fig 108 puncture. In the preceding figure this organ is shown fore- 



shortened, but in figure 108, the head and beak of the insect 

 are represented, highly magnified. The compound eves are 

 seen at dd, and the beak at b. The latter consists of several 

 parts, is cased in a horny substance, grooved down the middle, 

 and terminates in a fine, hard point. The inner wings of the 

 ^Boat-fly, when arrived at maturity, are fragile and delicate, 

 and are protected from injury, like those of many other insects, 

 by hard, shelly cases, under which they are neatly and com- 

 pactly folded. The insect is ornamented with long hairs, 

 which, along the lower part of the body and down the middle, 

 are arranged in thick tufts. These tufts appear to be intended 

 for the purpose of permitting the creature to float at plea- 

 sure, without any exertion, and this result is effected in the following way : the 

 Larva first rises to the top of the water, and then elevating the lower end of its 

 body above the surface, lifts up the rows of hair on either side of its body, suf- 

 fering the air to fill the channel or groove that they before occupied. Retaining 

 the air in this cavity, it thus becomes specifically lighter than the water, and now 

 floats at its ease upon the surface. When the insect wishes to descend, it smooths 

 down the rows of hair into their former place, by the aid of its feet, and thus 

 expelling the air, renders itself heavier than the water, and sinks. The margin 

 of the body of this little creature is naturally of a bright carmine, the central 

 portions of a yellowish brown, and the legs of a delicate straw color. Its food 

 consists of the eggs and larvae of water-insects, and it often awaits its prey by 

 lying at the bottom of the water with its beak upwards, ready for assault. In 

 this position it remains, until its victim, unwarily descending, falls in a moment 

 into the power of its destroyer. 



THE LARVA OF A SPECIES OF WATER-BEETLE. The eggs from which this 

 Larva is produced are found, in the spring and summer, adhering to the surfaces 

 of aquatic plants. They are enclosed in a bag, a little smaller in size than a 

 pea, which is fastened by a slight thread to the herbage. 



These eggs are readily hatched by placing them in a vessel of water, and 

 exposing them to the sun for a few days ; when the young soon appear, moving 

 about the fluid with great activity. At first they are of a dark hue, but in a 



