THE SPIDER 145 
Spider in no case being furnished with wings ; (d) in the 
manner of respiration—the Insect breathing through spiracles 
communicating with tracheae, whilst the Spider in addition 
to tracheae has two large breathing chambers or lungs ; 
(e) in the organs of sight—the Insect having both simple 
and compound eyes, and the Spider only simple eyes ; (f) 
in their life-history—the Insect passing through the egg, 
larval and chrysalis stages and growing no more after 
having emerged from the chrysalis ; and the Spider resem- 
bling its parents in all respects directly it is hatched from 
the egg ; (g) in their manner of spinning the silken thread— 
the Insect-larva, which spins a silken cocoon, passes the 
thread out from its mouth, and never weaves a web to 
catch insects, whilst the Spider is provided with spinnerets 
and combs for twisting the threads together; and weaves 
a snare for the capture of prey. 
Notrt.—The work suggested in this chapter might with 
advantage be deferred until some of that dealing with Insects be 
worked through. Pupils will then be in a position to appreciate 
the difference between the two forms. 
As in the case of Insects, large well-drawn diagrams or black- 
board drawings are essential. These should be sufficiently large 
to be seen by the entire class, and should avoid all unnecessary 
detail. It is this suppression of detail which often raises the 
home-drawn diagram above the level of usefulness reached by 
the published chart. Details which are not required at the time 
are for the moment suppressed, with the result that attention is 
concentrated on a few special characteristics, which are thus 
understood and impressed with thoroughness. 
The structure of the web could in many cases be observed out 
of doors—indeed this should be done wherever possible—and 
experiments should be made with the object of testing the strength 
of the silken fibre of which it is composed. Under favourable 
conditions the actual work of web-building might be observed. 
Lessons on the Garden Spider might be followed by those on 
other kinds of Spiders, e.g. Water Spiders ; or, in the case of the 
more advanced pupils, might be supplemented by information about 
various kinds of Spiders. 1f this be done, the work should be well 
illustrated by diagrams, drawings, and pictures. K 
