32 POND LIFE 



busily at work perched on various parts of the crustacean's 

 body. 



The eggs of cyclops are not dependent on the body heat of 

 the mother in order to hatch, for eggs separated from the 

 parent hatch in due course. 



Another crustacean that frequently falls victim to the pond- 

 hunter is Cypris. It resembles a minute brown mussel about 

 the size of a clover seed. On a close examination the likeness 

 to the mollusc increases. For Cypris lives in a bivalve shell 

 a shell that opens on one side only in the prescribed manner. 

 And when the little brown shell opens two long antennae 

 adorned with hairs are projected, and without further ado 

 away goes the little creature with surprising rapidity. 



Strange as it may seem, the male Cypris has never/been found, 

 and so reproduction must nearly always be parthenogenicaL 

 Cypris lays her eggs on aquatic plants. Weisman was success- 

 ful in keeping females of Cypris for eight years, and during 

 that time they produced eggs continually. An animal similar 

 to Cypris is Condona reptans, which is characterised by a longer 

 and more curved shell, lighter in colour, and also by its an- 

 tennae, which are minus the hair appendages so noticable in 

 Cypris. A glass jar containing a teeming population of these 

 little creatures as well as Daphnia and Cyclops is indeed a "thing 

 worth having." 



Every pond-hunter, every eater of watercress, knows Gam- 

 marus pulex the fresh-water shrimp. This little animal, a 

 giant if compared with cyclops, a Lilliputian when placed side 

 by side with a lobster, is common in every stream. Leaves, 

 dead and decomposing, decaying animal matter, in fact all 

 refuse, is its happy hunting-ground, and there Pulex plays to 

 its heart's content. But hunger, or at least the satisfying of 

 it, is the reason for its presence amongst the decomposing 

 matter. For Pulex is a scavenger, and is only too glad to 

 clear away by the destructive process of eating anything that 

 is suitable. The water-shrimp is not a fad, and is only too 

 pleased to eat healthy and fresh weeds when occasion needs. 



The males and females at certain seasons will be found 

 swimming together, the male holding his spouse by the neck, 

 by an enormous claw. The eggs are carried by the mother in 

 her front legs, which form a brood-pouch. The young, which 

 resemble their parents, but are redder in colour, on hatching 

 remain with the mother until dispersed. 



Asellus aquaticus the water hog or louse is far less active 

 than Pulex, in fact it will be found creeping sluggishly on the 

 mud or weeds, slowly as if fearing danger. Like the latter, it 



