Page:Popular Science Monthly Volume 37.djvu/356

356 growth. Dr. Packard, in his Guide to the Study of Insects, says that bed-bugs may be destroyed by "a preparation consisting of thirty parts of unpurified, cheap petroleum, mixed with a thousand parts of water"; and in the Popular Science News was published the following formula for a bed-bug poison: Into one half pint of alcohol put one ounce of camphor, with one ounce of pulverized sal ammoniac and one ounce of corrosive sublimate; to this add one half pint of spirits of turpentine and shake well before using. These solutions may be applied around the cracks and crevices of a bedstead;

benzine, too, may be used with good effect, and boiling water will destroy them, but the best preventive is perfect cleanliness. Curiously enough, they live parasitic upon domestic birds.

(Pulex canis).—The fleas, although having no wings, have until lately been classed with the flies (Diptera), but are now placed by many writers in an order by themselves, the Aphaniptera. During the past summer and fall there has been considerable annoyance caused in and around Boston by this troublesome insect, and owing to its habit of attacking man it was supposed to be the true human flea, but a letter of inquiry on the subject, addressed to an eminent entomologist brought the following reply: "So far as I know, we do not have the human flea in North America, and ours is Pulex canis, the dog and cat flea. It seems to breed in sandy cellars and such places at certain seasons."

The eggs of this flea are laid on the dog or cat, and, being sticky, adhere to the hair until almost ready to hatch, when they fall to the ground. These eggs are very small, white, and oblong, and but eight or ten are laid by one female.

The young larvæ are hatched in about a week, and their growth