INHABITANTS OF THE WATER-FILM 65 



deposited on various objects to be found in every pond and 

 stream, on stones, leaves, stems, and roots of water-plants, &c. 



The young on hatching have six legs. They are often para- 

 sites, and live the first part of their lives on higher animals 

 such as water-beetles. They attach themselves to their host 

 by their mouths, and hang there until they reach maturity. 

 Strangely enough during this period their legs fall off, and the 

 creatures remain fastened to their host by the mouth organs 

 Eventually they mature, and start a free existence, with the 

 proper number of legs, which is eight. One more moult takes 

 place before the creature is fully grown. 



Their eyes are simple in structure, similar to those of the 

 spider. In some cases they are very large and prominent. 



The species most often met with is a comparatively large 

 mite of a crimson hue, which when seen against a dark back- 

 ground attracts the attention of even the most unobservant. 



Water-mites are found in most parts of the world, and the 

 number of species is enormous. They are extremely hardy 

 and thrive in the aquarium, and are most charming little 

 creatures to keep, owing to their beautiful and varied colours. 



CHAPTER VI 



INHABITANTS OF THE WATER-FILM 



To the naturalist a pond would lose half its charm if none of 

 the Gerridae were present. For who does not admire those 

 graceful little insects skating on the surface of the water with- 

 out the slightest fear of drowning ? The water-film is capable 

 of resisting far greater weights, and their feet only produce 

 aquatic dimples where each leg rests. 



Although known as pond-skaters, the word skating does not 

 in any way describe the insect's movements, for a few powerful 

 strokes of the second pair of legs produces the necessary im- 

 petus, and the insect slides, rather than skates, along the water- 

 film. 



At times, especially when alarmed, the pond-skaters leap into 

 the air in the most astonishing fashion. The intrusion of a 

 whirligig beetle is often the cause, for although the beetle 

 shows no wish to interfere, yet in its rapid and erratic journey 

 it often collides with the pond-skaters, much to their horror, 

 causing the nervous little insects to spring up into the air 

 until the intruder has departed. During this acrobatic per- 



E 



