PARTHENOGENESIS AND ITS SEQUEL 305 



done daily, or at any rate frequently. Quickly these tiny 

 specks will grow into Brine Shrimps, translucent creatures 

 nearly half an inch long, swimming about back downwards 

 with a marvellously rhythmical movement of delicate 

 feet. In all probability no males will be found, but, 

 on the other hand, both sexes in almost equal numbers 

 may be present. The males may readily be distinguished 

 by their massive arms immediately behind the head, 

 for the purpose of embracing the females. 



Whence came these wonderful animals ? The mystery 

 is easily explained. The salt is genuine sea-salt, formed 

 in brine-pans, chiefly in the Mediterranean. As the 

 water evaporated the Shrimps it contained gradually 

 died ; but the eggs in the females became encapsuled in 

 the salt-crystals to hatch out long months after. In one 

 of my own experiments I succeeded with salt that I had 

 kept for more than a year. Of course, every sample of 

 salt experimented with will not yield successful results, 

 but failures are not expensive. Now in this brine-pan 

 there were myriads of other animals which were killed 

 outright : the Brine Shrimp is at least able to pass on 

 descendants by reason of the vitality of its eggs. Some 

 near relations of the Brine Shrimps live in fresh water 

 and possess similar powers of resistance to adverse 

 conditions. The Fairy Shrimp {Chirocephalus) is one of 

 these. Not unlike its cousin the Brine Shrimp in appear- 

 ance, it lives in shallow pools, such as have muddy 

 bottoms and are constantly liable to dry up. Birds 

 hunting by the margin* of the pool where the retreating 

 water has left a fringe of mud bear away more or less of 

 this on their feet and transport it to similar pools, or even 

 puddles. Such transplanted samples may easily contain 

 numbers of eggs of this tiny creature. Only a year or 



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