INSECT SUCKERS AND BITERS 217 
whether animal or vegetable, not even sparing our 
dish-cloths, if they have any grease upon them. 
Though we have most of us had cockroaches at one 
time or another in our houses, few people know any- 
thing of their history ; of the fact that the mother 
has only imperfect wings, while the father can fly 
about ; or that when a cockroach changes its skin it 
comes out white and soft, and is some time before it 
regains its dark reddish -brown colour. Nor is it 
likely that many people will have found the curious 
little horny cases of eggs (c, Fig. 74), shaped some- 
thing like a bean, and divided inside into separate 
compartments, which the mother carries about with 
her, half out of her body, till the eggs are nearly 
hatched, when she hides it in the cracks of the boards 
and mortar of the ovens. These cases contain about 
sixteen eggs, ranged neatly in two rows, and the 
edges of the case are strongly cemented together. 
As soon as the eggs are hatched, the young 
cockroaches give out a fluid which loosens the 
cement, and they come out into the world small, 
wriggling creatures (y, Fig. 74), with all the rings 
of their body conspicuous, because their wings are 
not yet grown. 
But above all, few people probably would give 
cockroaches credit for being intelligent animals, and 
yet an escape of cockroaches which happened in the 
house of a friend of mine shows them to be more clever 
than is generally supposed. The house being infested 
with these anrmals, the cook laid a trap to catch them, 
made of a box with two strips of glass sloping in- 
wards from the sides, and it happened that the edges 
\& r ere only about an inch from the bottom of the 
