Cockroaches, Locusts, Grasshoppers, and Crickets 127 
and humid and the roach’s table is well set with good things. Almost any 
sort of dry organic matter suits their taste; bread, crackers, miscellaneous 
cold-lunch delicacies, the paste of bookbindings and wall-paper, leather, 
woolens, and even their own egg-cases and cast skins making up the dietary. 
The fo’k’sel and galley of ships are the roaches’ special joy; the hotels and 
restaurants of tropic and subtropic lands house swarms of these bill-evading 
guests. From Mazatlan, Mexico, a naturalist sent me quarts of large native 
American roaches (.Periplaneta americana), which he readily scooped up 
from his bedroom floor. Ships come into San Francisco from their long 
half-year voyages around the Horn with the sailors wearing gloves on their 
hands when asleep in their bunks- in a desperate effort to save their finger¬ 
nails from being gnawed off by the hordes of roaches which infest the 
whole ship. A few of our species still live outside under stones and old 
logs, but most of them have learned that an easier life awaits them in the 
kitchen. 
The roaches compose the Orthopterous family Blattidae, and are an 
ancient and persistent insect group. In Carboniferous times, before flies, 
butterflies, bees, and wasps had come into existence, cockroaches were 
the dominant insects. The body in all is flattened and slippery with the 
legs adapted for quick running, so that the insects are well fitted to escape 
safely into narrow cracks and crevices. The head is concealed from above 
by the expanded shield-shaped dorsal wall of the pro thorax (pronotum). 
Wings are present in most species, the front pair 
leathery and serving, when the wings are folded, to 
cover and protect the larger, thin, membranous 
hind pair. In some forms the females are wingless, 
and the indoor habit may be held responsible for 
the lessened usefulness and resultant loss of the Fig - : I 57 - — Egg-case of 
wings. The mouth-parts are fitted for biting hard naturai aC s?ze.) Thre6 tim6S 
dry substances, the jaws being strong and toothed. 
The eggs are laid in small purse-like, horny, brown cases (Fig. 157), which 
are usually carried about by the female until the young are ready to issue. 
The young grow slowly, requiring probably about a year, in most species, 
to become fully developed. From the beginning, the young can run about 
and take care of themselves, eating the same kind of food as the adults. 
They moult several times during growth, and at each moult the wing-pads 
are a little larger. 
There are four common species of cockroaches found in dwellings in this 
country, only one of which is native. This is the large American roach, 
Periplaneta americana , about ij inches long (to tip of folded wings), light 
brown in color, and with the wings expanding nearly 3 inches. This species 
is abundant in the middle and western states, having gradually extended 
