THE FRESH WATERS 183 
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 in- 
teresting facts about the water-spider, for in- 
stance, how she arranges tags of silk among 
her hair, which probably help in entangling 
the air-bubbles. For reasons, rather difficult 
to explain, she never gets wet. But the big 
interest is just that this spider found an empty 
