80 POND LIFE 



say, free swimming. But it seldom does so, and prefers to 

 fasten to some support. 



The Rotif era are characterised by one general rule, and that is 

 that the females preponderate, whilst the all-important " man " 

 is noticeable by his absence. In this kingdom the gentler sex 

 has no need to break down cell tissue for " their rights," for 

 the male is not only rare, but, in addition, lacks digestive 

 organs, and so is therefore much handicapped. In fact he 

 only appears when he is wanted, and never shows his face 

 otherwise. Owing to the rarity of the males, the production 

 of unfertilised (known as summer) eggs is usual. These eggs 

 frequently hatch within the parent. Rotifers also produce 

 fertilised winter eggs, so called as they are able to resist 

 adverse conditions. It need not be remarked that the male is 

 essential for the production of these winter eggs. 



We now come upon a most curious but wonderful scheme, 

 showing how Nature looks after her children, although they 

 may be microscopical. As the summer wears on, and the pond 

 becomes depleted of its water, the unfertilised females produce 

 special eggs, which hatch into males only. Winter eggs are 

 wanted to resist the coming drought, and these can only be 

 produced by union with the male. So numbers of males are 

 produced so as to fertilise the females, and thus lead to the 

 production of the required winter eggs. 



The Rotifera are not examples of longevity, at least from 

 man's point of view, for the males die in two or three days, 

 whilst the females have the good fortune to live to the ripe 

 old age of a fortnight. But during this short lifetime no 

 valuable seconds are wasted. Sleep probably plays no part. 



Maupas has found that in thirteen days the female rotifer is 

 able to produce about fifty eggs, and it is therefore hardly 

 surprising that rotifers are found in enormous numbers in all 

 ponds and streams. 



The earthworm, owing to its abundance, is so well known that 

 man is liable to imagine that it is " the '' type of the worm 

 family, and that every worm should necessarily resemble 

 Lumbricus Terrestris to at least a noticeable extent. But it 

 is not so : L. Terristris is only a type of one kind of worm, and 

 there are very many kinds vastly different in appearance, and 

 totally unlike in their habits. 



The Polyzoa, known by some as Moss Polypes, bear little, if 

 any, resemblance to the earthworm. In fact for several years 

 they were classified as members of the jelly-fish family, which 

 is not surprising, as their appearance is certainly similar. When 

 the matter was carefully inquired into, although the creature 



