MINUTE AQUATIC ANIMALS. 73 



short time they shed their skin, daring which process their color fades ; at the 

 same time their vivacity forsakes them and they abstain from food. 



As they recover, their color changes again, and diversified tints adorn their 

 bodies. These creatures are extremely voracious ; for if they are placed in 

 water with other insects, the latter are soon found to be either mutilated or 

 destroyed. 



This Larva is seen of its natural size in figure 109, and a magnified representa- 

 tion is given in figure 110, which exhibits the animal soon after it has cast its 

 skin : when, on account of the transparency of the new skin, it is in the best 

 condition to be viewed by the microscope, as the whole interior organization is 

 then visible. This insect is furnished with two strong jaws, like a pair of bent 

 pincers, which move horizontally and cross each other when closed. Their color 

 is a bright chestnut, deepening in tint towards the points, which are hard and 

 sharp. The animal seizes its prey with these instruments, and forcibly draw- 

 ing it towards itself, makes an incision on the body and sucks out the juices. 

 Unless its prey is of great strength the Larva does not kill it before eating, but, 

 seizing on any part within its reach, devours it while its victim is alive. Having 

 finished this portion, it turns the insect round and feeds upon a fresh part, and 

 thus continues its repast until the whole of its prey is consumed, except the 

 skin. 



If the object of attack is a strong, aquatic animal covered with a shell, the 

 Larva either seizes and holds it firmly grasped until it is exhausted by its efforts to 

 escape ; or, springing at it from time to time, cuts oft' its limbs in succession with 

 its powerful nippers ; then, turning the disabled animal upon its back, the ferocious 

 creature pierces the mutilated body, and imbibes its contents. In respect to the 

 other parts of the animal, feelers are seen branching out from the head, each 

 composed of four pieces, connected by joints. On either side of the head is a 

 cluster of eyes, six in each cluster ; in some species they are arranged in a circle 

 at equal distances from one another, while in others three or four are united in 

 a group with the rest a little separated from them. The organs of respiration 

 are seen in their greatest development at the head, and their course from thence 

 to the tail, through the entire length of the animal, is indicated by the dark 

 lines in the figure. At the tail the different parts unite and terminate ; they 

 are not simple in their structure, but numerous lateral subdivisions are thrown 

 out between the extremities of the main organs. 



The entire body of the animal is composed of rings, decreasing in size 

 from the head to the tail, which is forked, and consists of two strong spines 

 with smaller ones branching from their sides. When one of these is destroy- 

 ed, Pritchard observed it to be replaced by another, which seldom, however, 

 attains the size of that which is lost. The Larva is provided with six legs, each 

 consisting of three joints ; bristling with formidable spines, fringed with hairs, 

 and armed at the extremities with strong claws. The front part of the head, 

 immediately below the jaws, is furnished with an arrangement like the teeth of 

 a saw ; but whether this apparatus is really composed of teeth has not yet been 



