ti itZ Marvels of the Universe 
1116). A number of loose loops hang about the ball and are probably intended to make it difficult 
for ichneumon-wasps to attack it. This spider only lays about six eggs. 
A remarkable egg-cocoon is that made by Agroeca, a spider that is plentiful in pine-woods. 
With the stalk by which it is suspended, it is the shape of a wine-glass, with the mouth closed by a 
flat sheet of tissue. When new, it is perfectly white, and in contrast to the dark-red trunks of the 
pines to which it is attached is a very conspicuous object. But the spider has no intention of its 
attracting the notice of passers-by. She hunts about on the bark and finds all sorts of minute 
odds and ends, which she industriously sticks all over her nice clean-looking work, until it appears 
to be merely some bits of dirt that have become caught in stray wisps of an old web. We show 
photos of the two stages (page 1117), and it will be noticed that in the later condition it is difficult 
to see the outline of the disguised cocoon 
against the dark background supplied by the 
pine-trunk. This has always appeared to us a 
remarkable case of spider-wisdom—the spiders 
are all well endowed with wisdom, even though 
it be only inherited wisdom. First of all, there 
is the clever manipulation of the silk filaments 
to form this well-designed cocoon, and then 
the wisdom of disguising it that it may not 
attract the attention of birds, ichneumon-wasps, 
etc. It is a psychological heresy to attribute 
to such creatures any knowledge of the reason 
why they do these things; but the observant 
naturalist is bound at times to be a _ psycho- 
logical heretic. There are two _ species of 
ichneumon-wasp that endeavour to lay their 
eggs in the eggs of this spider in spite of all 
her care. 
Somewhat similar in texture to the cocoon 
of Agroeca is that of Theridion. The latter 
spider constructs a papery cocoon, of which 
the ground plan may be said to be spherical 
with the addition of several spikes sticking out 
from it. It is attached to the under-sides of 
[By F. Bnock, F.LS. leaves, where it is easily overlooked. Now this 
WEIS WINGS COVED is wonderfully like a gall that is formed on 
The wing-covers are closed down securely over the wings, 
antl dis BAe 6 RO GE (oe coi co ee, US HSE OCS Ot Une messiemn, anal One WonGes 
insect. whether the egg-cocoon of Theridion is intended 
to resemble that gall (see page I140), and so to be passed over by those birds that hunt for 
spiders. An argument against this is that some galls are systematically explored by certain birds 
for the grubs they contain, and in their case the resemblance would tell against the spiders. 
Still, the resemblance is remarkable and worthy of note. 
Some spiders construct their egg-cocoon within a tent formed by spinning two or three wayside 
leaves together ; and several species that live under stones or in tunnels in the earth or old walls 
keep their egg-cocoons near them in their dens. Some North American representatives of our 
Garden Spider string their egg-bags to the ropes of their snares, so that they may have them under 
close observation whilst they are attending to their business of trapping insects. 
The sub-aqueous, bell-shaped home of the Water Spider may also be considered as an egg-cocoon, 
for it is there that her eggs are kept, and it serves for a time as a nursery for her young ones. A 
