268 SUPPLEMENT ON THE CARNIVOROUS FAMILY 



explosion, and the action of the vapour, which it then sheds, 

 occasions a very sensible degree of pain, and one of long 

 duration. 



The brachinus displosor is found, like the other species in 

 general, under stones, and under heaps of rotten plants in 

 the dry and elevated grounds of Navarre, Arragon, and 

 Catalonia. Mr. Kirby says, above, that its caustic smoke 

 reddens white paper, but M. Leon Dufour says that it is 

 blue, in which this change is wrought. Probably both are 

 right. Be that as it may, the yellow or brown fluid, which 

 becomes fixed immediately, and in the form of a crust, lets 

 escape, immediately after its emission, some air-bubbles, and 

 presents an appearance of fermentation. If the animal be 

 disturbed about the corslet, the surface of the elytra is soon 

 powdered over with a sort of acid dust, resulting from the 

 explosions. These properties are common to the two sexes. 



There are some anatomical observations given by M. Du- 

 four, relating to these insects, that are well worthy of the 

 attention of the reader, and of which we shall make a brief 

 abstract. 



The apparatus of the organ which produces the smoke, is 

 double, that is to say, there is one on each side in the abdo- 

 minal cavity. It consists of two very distinct bodies, one of 

 which is the preparatory organ, the other the conservatory 

 organ. The first is more interior, and presents itself under 

 two different aspects, according as it is contracted or dilated. 

 In the first case it is a whitish body, irregularly rounded, 

 soft, appearing glandular, placed under the last rings of the 

 abdomen, opening by one end into the reservoir, and con- 

 stantly terminating at the other in a very long and narrow 

 thread. In the second case, or when it is dilated, it resem- 

 bles an oblong membranous diaphanous sac, filled with air, 

 occupying then the entire extent of the abdomen, and ap- 

 pearing free, with the exception of the extremity which opens 



