THE FRESH WATERS 183 



live underneath the water. It is the female 

 water-spider who is particularly admirable, so 

 we shall henceforth say "she." She spins a 

 flattish web beneath the water, and moors it with 

 silk threads like tent-ropes to stones and weeds. 

 A special line runs up to the surface and is fixed 

 to a floating plant. Up and down this rope the 

 spinner goes many times ; at the surface she 

 gets air entangled in the hairs of her body ; she 

 climbs down, looking like a drop of quicksilver 

 in the water the air glistens so ; she brushes 

 her hair with her legs, and the air-bubbles are 

 caught underneath the web, which thus becomes 

 buoyed up like a dome or like an anticipation 

 of a diving-bell. After many journeys up and 

 down the web is full of dry air, and there the 

 spider deposits her eggs and rears her young. 

 Sometimes when she is in a hurry she gets into 

 the empty shell of a water-snail and manages, 

 we do not quite know how, to fill it with air 

 brought down from the surface. There are 

 many interesting facts about the water-spider, 

 for instance, how she arranges tags of silk 

 among her hair, which probably help in en- 

 tangling the air-bubbles. For reasons, rather 

 difficult to explain, she never gets wet. But 

 the big interest is just that this spider found an 



