STUDIES IN ANIMAL LIFE. 43 



Fig. 7. LABVvE or THE GNAT in two different stages of development 

 (magnified). 



cast aside this mask (larva means a mask), and 

 emerge a perfect insect. The other (B) is in a 

 much less matured condition, but leads an active 

 predatory life, jerking through the water, and fast- 

 ening to the stems of weed or sides of the jar by 

 means of the tiny hooks at the end of its tail. The 

 hairy appendage forming the angle is not another 

 tail, but a breathing apparatus. 



Observe, also, those grotesque Entomostraca* 

 popularly called "water-fleas," although, as you 

 perceive, they have little resemblance in form or 

 manners to our familiar (somewhat too familiar) 

 bed-fellows. This (Fig. 8) is a Cyclops, with only 

 one eye in the centre of its forehead, and carrying 

 two sacs, filled with eggs, like panniers. You ob- 



* Entomostraca (from entomos, an insect, and ostracon, a shell) 

 are not really insects, but belong to the same large group of ani- 

 mals as the lobster, the crab, or the shrimp L e., crustaceans. 



