CYCLOPIDiE. 
189 
The species belonging to this family are to be found 
both in fresh water and in the sea. The fresh-water 
species abound in the muddiest, most stagnant pools, and 
in the clearest springs, and the ordinary water with which 
the inhabitants of London are supplied for domestic 
purposes often contains them in great numbers. The 
marine species are to be found frequently in immense 
quantities in small pools on the sea shore, within high- 
water mark, living among the sea-weeds and coral- 
lines, which so elegantly fringe the beautiful little wells 
and clear round pools which are hollowed out in the rocks 
on the coast, and are to be met with in equal profusion 
in the open ocean, where, by the curious luminous pro- 
perties they possess, they assist in producing that beautiful 
phosphorescent appearance of the sea, which formerly 
puzzled naturalists to discover the cause of. It is 
amazing when we examine the pools of water in our 
fields or sea shores, to find such infinite myriads of little 
creatures sporting about in all the enjoyment of existence ; 
and it is exceedingly curious and interesting to know the 
extraordinary fertility of such apparently insignificant 
creatures. Specimens of the Cyclops quadricornis are 
often found carrying thirty or forty eggs on each side; # 
and though the other species, which have only one external 
ovary, do not carry so many, still the number is very 
considerable. Jurine has with great fidelity watched the 
hatching and increase of the Cyclops quadricornis in par- 
ticular, and has given a calculation which shows the 
amazing fertility of the species. He has seen one female 
isolated lay ten times successively, but in order to speak 
within bounds, he supposes her to lay eight times within 
three months, and each time only forty eggs. At the 
end of one year this female would have been the progenitor 
of 4,442,189,120 young ! ! The first mother lays 40 
. * Leeuwenhoek says, that in the specimens which occurred to him of the 
quadricornis, he counted the eggs in the ovary and found them arranged 
three or four in breadth, and nine or ten in length. — Epist. ad Soc. Reg. 
Aug., p. 138. 
