HABITS OF CENTIPEDES. 91 



It may be laid down as an axiom that in general no 

 insect destroying insect can be artificially propagated with- 

 ont multiplying its often injurious prey ; the Australian 

 Coccinella, used to devour the plant lice on the Florida 

 orange trees, requires no artificial aid in rearing. 



It may be interesting to note in this connection one 

 insect whose value as a domestic fly destroyer is probably 

 not appreciated. I refer to a species of Ccrmatia, proba- 

 bly forceps, a spider-like centipede having extremely long 

 and slender legs, the body of which is about two inches 

 in length, and its speed marvelous. It is of frequent 

 occurrence in dwellings in New York City and Brooklyn. 

 During the day it retires to the darkness and dampness 

 of closets, leaky basins, and cellars, but at night issues 

 forth, traversing the entire house, and frequently stations 

 itself head downward along the upright " trim " of the 

 kitchen or wherever flies are abundant, and \yitli mem- 

 bers extended seizes and mercilessly slays every fly pass- 

 ing within its reach. If unable to devour all its captures, 

 the first is allowed to drop to the floor after receiving a 

 fatal bite and another substituted of the several simul- 

 taneously imprisoned and buzzing at different points be- 

 tween its legs. Its appetite does not seem to become 

 readily satiated, one specimen capturing flies for an hour 

 and a half, when my patience became exhausted and it 

 was taken into custody. One day's confinement in a dry 

 box caused the insect to shrivel and die. In spite of its 

 usefulness, I have not encouraged it in my house, prefer- 

 ring a whitewashed cellar with dry cement bottom and 

 sanitary plumbing to its company. (According to La- 

 treille the bite of insects of this genus is poisonous.) 



Inasmuch as the result of my investigation has failed to 



