286 THE INSECT WORLD. 
among them, the Blatta Germanica and the Blatta Laponica, 
which are to be met with in the woods round about Paris, have 
domesticated themselves in dwellings of the northern countries. 
They are a quarter of an inch in length. The Russians pretend 
that the former was imported from Prussia by their army, on its 
return from Germany, after the Seven Years’ War (1756—1762). 
Till this period it was unknown at St. Petersburg, where now-a- 
days it is met with in great numbers. It lives in houses, and 
eats pretty nearly everything, but prefers white bread to flour and 
meat. The Blatta Laponica devours the smoked fish prepared for 
the winter. 
The German naturalist, Hummel, made some interesting obser- 
vations on the development and habits of the very prolific Blatta 
Germanica. It lays its eggs in a silky capsule, which is in the 
form of a bean, with two valves in the interior. This is drawn 
about for some time appended to the extremity of the abdomen, 
and after a time abandoned. 
Hummel placed under a bell-glass a female cockroach and a 
perfect egg-pouch, which had only just been abandoned by another 
female. He saw the cockroach approach:the bag, feel it, and turn 
it about in all directions. She then took it between her front 
legs, and made a longitudinal opening in it. As the opening grew 
wider, little white larvae were seen to come from it rolled up and 
attached two together. The female presided at this operation. 
She assisted the larve to set themselves free, aiding them out 
gently with her antenne. Jn a few seconds they were able to 
walk, when she ceased to trouble herself about them. 
The larvee change their skin six times before reaching the per- 
fect state. When they come out of their skin they are colourless, 
but the colour comes in a few minutes. At the fifth moult, which 
takes place three months ‘after birth, they become pupz, with 
rudimentary wings, the whole shape of the insect bemg well 
marked. The sixth, or last moult, takes place at the end of six 
. weeks. The pupa is now changed into a perfect insect. The 
female is distinguished from the male by the greater size of her 
abdomen. 
The most destructive of the Blatte, or Cockroaches, are those 
which have been imported into Europe by the ships coming from 
