ORTHOPTERA. 221 



the eggs, or could possibly promote their maturation 

 if it were. The temperature of the body of a cold 

 blooded animal is always in equilibrium with the sur- 

 rounding element, and it could, therefore, impart no 

 additional heat to objects subjected to the same in- 

 fluence in this respect as itself. The case is different 

 when multitudes are congregated within a narrow 

 space ; heat is then generated, as is well known to be 

 the case in bee hives. 



FAM. BLATTIM;. 



THE members of this family are very unlike the pre- 

 ceding, and they may be said to differ nearly as much 

 from all the other tribes with which they are asso- 

 iated. Their bodies are in general broad, oblong, 

 and depressed, the abdomen almost completely covered 

 by the tegmina, which considerably overlap each other 

 on the back, and wholly cover the under wings. The 

 bead is curved inwards beneath the prothorax ; the 

 antennae very long, setaceous, and flexible, inserted 

 in a notch in the inner side of the eye ; the two lower 

 joints of the maxillary palpi are somewhat globular, 

 the terminal one (as is likewise the case with the 

 corresponding joint of the labial palpi,) pretty thick 

 and truncated. A conical and articulated appendage 

 projects from each side of the abdomen behind. The 

 legs are thickly armed with spines on the tibia, and 

 all the tarsi consist of five joints. 



Most of these insects are of a uniform brown colour, 

 a hue well adapted to their habits and the nature of their 

 haunts. A few, which usually frequent flowers, are 



