ANNULOSA. 545 



expire in a few days after tlic important end has been ac-^ 

 complished, — the males usually before the females. Such 

 species, in general, require but little food in the mature 

 state. Others outlive several impregnations and several 

 years, and, during this period, require a constant supply of 

 food. 



There are many circumstances, however, which occasion 

 a premature death to this tribe of animals, in all the stages 

 of their existence. They are the food of many quadrupeds, 

 birds, reptiles, and fishes. These animals seek them in 

 their places of retreat ; and but for the circumstance that 

 a superabundant supply is provided, we may be surprised, 

 that the continuance of the species is preserved. They are 

 not destitute, however, of means of escape or defence. 

 Many of them so exactly resemble the substances on which 

 they feed, as readily to escape the eye of the foe. Some of 

 the crabs attach, by a glutinous matter, the leaves of sea- 

 weeds to their body, so as to conceal completely their form, 

 and secure them from detection. Some are protected by 

 hairs and spines, the offensive attitudes they assume, and 

 the disgusting odours they emit. The Brachinus crepi- 

 tans, when pursued by its great enemy, the Calosoma syco- 

 phanta, a rare British beetle, emits from its anus repeated 

 explosions of blue smoke, having a disagreeable smell, 

 Avhich stops the progress of the assailant. In another 

 species, B. displossor, the scent of the smoke is pungent, 

 and resembles that of nitric acid. Other insects, when irri- 

 tated, emit a strong smelling fluid, from glands seated at 

 the anus, which have been termed Osmateria. The jaws 

 are employed by some species, and the sting by others, as 

 means of defence in the hour of danger. This last organ 

 is essentially connected with the business of reproduction, 

 and is seated at the ovipositor of the female. In the bee, 

 the apparatus of the sting consists of the coriaceous lamin» 



VOL. II, M m 



