

TERRESTRIAL 215 



heather twigs, and then one may have an object lesson which 

 justifies the whole excursion. 



Spiders. A profitable thing to do on a summer day is simply 

 to sit down among the heather and to remain quite still, watching 

 the busy life in the miniature jungle around us. We see the 

 mother spiders carrying little balls of silk below the front part of 

 the body. These are cocoons containing eggs or young spiders. 

 If we catch one of the spiders and gently remove the silken cradle 

 we may see the careful but very short-sighted mother searching 

 for it. When she comes by chance within a certain short distance 

 of it she gets the scent and soon recovers her treasure. To know 

 the names of these moorland spiders is not an easy matter, 

 especially since the best book (Blackwell's British Spiders) is large 

 and expensive, but that is not a matter for elementary Nature 

 Study. What is really important is to look carefully at the 

 spiders one does see, to distinguish the four or five kinds that 

 one sees oftenest at that place on that summer afternoon. Among 

 the heather there are different kinds of webs to be looked at and 

 sketched, and there are cocoons " spiders' nests " which are 

 fastened to the twigs and not carried about. 



Water - Spider. In a moorland pool which means a com- 

 paratively " wild " place we may look for the true water-spider 

 (Argyroneta aquaticus), to find which marks a red-letter day. It 

 spins a web beneath the water, mooring it to water-weeds ; it 

 buoys this up with air brought down from the surface entangled 

 in its hairs ; and there it lays its eggs. In some cases it uses the 

 empty shell of a freshwater snail for its nest, fixing it in a suitable 

 position with threads of silk and filling it up with air as before. 

 The water-spider will live for a while in captivity, and by watching 

 it close at hand the pupils may convince themselves that the 

 silvery appearance (to which it owes its name Argyroneta) is 

 due to bubbles of air held among the hairs of the body. 



Centipedes. Another expedient on the moor is to turn over 

 loosely lying stones, for instance near the half broken-down wall 

 that separates the moorland from wood. There one may see 

 beautiful centipedes, like Lithobius, pointing them out to the 

 pupils as among the forerunners of the insects, and among the 

 persecutors of earthworms. Their lively and graceful movements 



