104 REPOET OF STATE GEOLOGIST. 



numbers, a fetid, nauseous odor, well known as the 'roachy' odor, 

 which is persistent, and can not be removed from shelves and dishes 

 without washing with soap and boiling water. Food supplies so 

 tainted are beyond redemption. This odor comes partly from their 

 excrement, but chiefly from a dark colored fluid exuded from the 

 mouth of the insect, with which it stains its runways, and also in 

 part, doubtless, from the scent glands, which occur on the bodies of 

 both sexes between certain segments of the abdomen, and which se- 

 crete an oily liquid possessing a very characteristic and disagrL'eal)l(' 

 odor. It frequently happens that shelves on which dishes are placed 

 become impregnated with this roachy odor, and this is imparted to 

 and retained by dishes to such an extent that everything served in 

 them, particularly liquids, as coffee or tea, will be noticed to have a 

 peculiar, disgusting, foreign taste and odor, the source of which may 

 be a puzzle and will naturally be supposed to come from the food 

 rather than from the dish." 



The Oriental roach is probably the most carnivorous of all our 

 Blattidse, though, like most others, it is fond of starchy food. It is 

 known to feed npon meat, cheese, woolen clothes, and even old 

 leather, and is said to be especially fond of the festive "bed-bug," 

 Acanthia lectularia L., which soon disappears from a house infested 

 with the Oriental roach. This roach is, however, far too great a nui- 

 sance in itself to be introduced as a means of eradicating even the 

 bed-bug. 



The eggs of the Oriental roach are sixteen in number, and the 

 large, horny capsule or ootheca in which they are packed is carried 

 about by the mother for a week or longer when she drops it in a Avarm 

 and "sheltered place. Along one side of the capsule, which resembles 

 in form and color a diminutive seed of the papaw, Asimina triloba 

 Duval, is a seam where the two edges are cemented closely together. 

 Wlien the young are hatched they excrete a liquid which dissolves 

 the cement and enables them to escape without assistance, leaving 

 their infantile receptacle as entire as it was before they quitted it. 



This species is notably gregarious in habit, the individuals living 

 together in colonies in the most friendly way, the small ones being 

 allowed by the larger ones to sit on them, run over them and nestle 

 beneath them without a show of resentment. The young pass 

 through a variable number, sometimes as many as seven, moults, the 

 skin splitting along the back and the insect emerging white and soft, 

 but soon hardening and assuming its normal color. 



Besides the remedies given on a previous page for roaches in gen- 

 eral, a simple trap has been tried by Mr. Marlatt which was fairly 



