ADAPTATIONS isi 
thrust into a pouch or fold of skin along the abdomen, 
where they are kept until they are able to take care of 
themselves (Fig. 74). This is an interesting and ingenious 
adaptation, but less specialized and 
less perfect an adaptation than the 
conditions found in ordinary mam- 
mals. 
Among the insects, the special 
provisions for the protection and 
care of the eggs and the young are 
wide-spread and various. Some of 
those adaptations which take the 
special form of nests or “homes” 
will be described in a later chapter 
(see Chapter XV). The eggs of Fic. 77.—Giant water-bug (Ser- 
the common cockroach are laid in 740. Mule carrying caus 
small packets inclosed in a firm wall 
(Fig. 76). The eggs of the great water-bugs are carried on 
the back of the male (Fig. 77); and the spiders lay their 
eggs in a silken sac or cocoon, and some of the ground or 
Fig. 78.—Cocoon inclosing the pupa of the great Ceanothus moth. Spun of silk by the 
jJarva before pupation. 
running spiders (Lycoside) drag this egg-sac, attached to 
the tip of the abdomen, about with them. The young 
spiders when hatched live for some days inside this sac, 
feeding on each other! Many insects have long, sharp, 
