AND THEIR INHABITANTS. 221 



highly-organized being, having eyes, but these minute 

 forms require an object-glass of about sixty diameters ; 

 a large number of the Desmidacea were also here. 



February is not much more productive than January, 

 but still our brooks afford the water-fleas, Cyclops and 

 Daphnia pulex, and the Hydra vulgaris, a radiated 



SKELETON WHEELBEARER. 



(A Rotifer.) 



animal, which attaches itself to minute plants, the 

 empty shells of molluscs, and the empty cases of 

 caddis-worms. The latter attach to themselves nu- 

 merous shells, sticks, and other substances, which 

 cause them to assume a most extraordinary appear- 

 ance. In the summer they are found creeping, as in 

 the cut, on aquatic plants. 



The month of March is much more favourable. 



