OBSERVATIONS ON INSECTS AND VERMES. 413 



hearth swarms with young crickets, and young blatt<z molendinaria 

 of all sizes, from the most minute growth to their full proportions. 

 They seem to live in a friendly manner together, and not to prey 

 the one on the other. 



August 1792. After the destruction of many thousands of 

 blattce. molendinaria, we find that at intervals a fresh detachment 

 of old ones arrives, and particularly during this hot season ; for 

 the windows being left open in the evenings, the males come 

 flying in at the casements from the neighbouring houses, which 

 swarm with them. How the females, that seem to have no perfect 

 wings that they can use, can contrive to get from house to house, 

 does not so readily appear. These, like many insects, when 

 they find their present abodes overstocked, have powers of 

 migrating to fresh quarters. Since the blatice have been so 

 much kept under, the crickets have greatly increased in number. 

 WHITE. 



GRYLLUS DOMESTICUS. HOUSE CRICKET. 



November. After the servants are gone to bed, the kitchen 

 hearth swarms with minute crickets not so large as fleas, which 

 must have been lately hatched. So that these domestic insects, 

 cherished by the influence of a constant large fire, regard not the 

 season of the year, but produce their young at a time when their 

 congeners are either dead, or laid up for the winter, to pass away 

 the uncomfortable months in the profoundest slumbers, and a 

 state of torpidity. 



When house -crickets are out, and running about in a room 

 in the night, if surprised by a candle, they give two or three 

 shrill notes, as it were for a signal to their fellows, that they 

 may escape to their crannies and lurking holes, to avoid danger. 

 WHITE. 



CIMEX LINEARIS. 



August 1 2th, 1775. Cimices lineares are now in high copulation 

 on ponds and pools. The females, who vastly exceed the males 



