276 PEBSH-WATEE AQUAEIA. 



provided with. Cyclops, water-fleas, and the like, as food. The 

 Mite's manner of seizing its prey is interesting;. 



Aquatic Worms are not, as a rule, considered either ornamental 

 or desirable in an aquarium. Some of them, however, are 

 very useful there, and by no means uninteresting. For 

 instance, the Naidce are active and graceful little creatures. 

 They seem to be nearly always in motion, spending the 

 greater part of their time either in crawling over weeds or 

 swimming through the water. Their movements are assisted 

 by small bristles, which are distributed over various portions 

 of their bodies. Their average length may be said to be 

 about |in. ; and they have great powers of elongation and 

 contraction, especially with regard to their head, which can 

 be easily distinguished from the rest of the body. They are 

 both oviparous and multiply by spontaneous division. Their 

 food chiefly consists of water-fleas and other minute animals. 

 These restless little Worms can generally be found near or 

 among the roots of aquatic plants. A Naid Worm is a very 

 interesting object under a microscope — its bristles, of which 

 there are two kinds, being beautifully transparent. 



As one goes about the country during the spring and 

 summer months, he will be almost certain to notice, if at 

 all observant of nature, patches of red at the bottom of 

 shallow pools of water. These red patches are caused by 

 the congregation of many small, interesting, and useful Worms 

 (Tuhifex rivulorum), known commonly as the Eiver, or Summer, 

 Worm. If the water above them is disturbed, they will 

 immediately disappear by withdrawing themselves into their 

 burrows in the soft mud. They soon, however, recover from 

 their fright, come out again, and at once recommence the 

 restless movements which, with their numbers and bright 

 colour, attracted the attention of the passer-by. It is the tail- 

 end of the animal which is protruded out of the mud. The 

 skin of these Worms is so thin and transparent that not 

 only can the blood be seen through it — hence the title of 

 " red " — but also all the internal arrangements of the creatures 

 may be plainly observed. The life-history of T. rivulorum 

 is very similar to that of the common earth-worm, to which 



