ANIMAL LIFE IN PONDS & STREAMS 



front of the head there is a black or red patch — 

 the eye. Very frequently we may meet with a 

 specimen carrying a relatively large bladder-like 

 body on each side of its abdomen. These bladders 

 which are each about one-third as long as the 

 creature which carries them, are egg-sacs. 



If we are able to secure one or two specimens 

 with egg-sacs attached, we can study the young 

 Cyclops without much difficulty. Take a small 

 glass tube — a test-tube as used by chemists will 

 serve admirably — partly fill it with pond water and 

 add a little water weed, then introduce the egg- 

 bearing females and place in the light. We must 

 watch the tube from day to day, and before long 

 it will be evident that the young ones have arrived 

 in the world, for we shall have no difficulty in seeing 

 dozens of little white specks swimming about in the 

 water and settling on the sides of the tube. We 

 must remove one carefully on the end of a glass rod 

 or on a paint brush and examine it in a drop of 

 water under the microscope. This young creature 

 is totally unlike its parent, it is oval and possesses 

 three pairs of stiff bristles, of which the first pairj 

 are simple and the other two pairs are branched. | 

 Although the bristles are used solely for swimming at i 

 this stage, it may be of interest to mention that in 

 the adult Cyclops they become transformed into 

 jaws and the two pairs of organs we have al- 

 ready examined. At the front end of the oval body 

 we can closely distinguish the single eye, which ( 

 jiersists throughout life. 



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