INSECTS. 229 



phagus is not dilated. Those which have the stomach mem- 

 branous and dilated, live generally on the nectar of plants, such 

 as the bees, butterflies, &c. ; those in which the stomach is mus- 

 cular are chiefly the Hemiptera ; and those in which this vis- 

 cus is not dilated feed commonly on leaves or roots, which they 

 gnaw and eat. The insects which have a double stomach are 

 the Coleoptera which feed on living prey, such as the Hydro- 

 canthari, the Cicindeletce, and the Carablcce. They are cha- 

 racterized also by six palpi. The first of their two stomachs 

 is short and fleshy, and forms a species of gizzard, where the 

 muscles are disposed in slender filaments ; the second forms a 

 long membranous canal, which, when examined under the mi- 

 croscope, appears hairy. This villosity is supposed to be com- 

 posed of tubes adapted to taking up the surrounding fluids. The 

 Brachelytra or the Staphylini of Linnaeus have two stomachs, 

 and the same is observed in the bees. The greater part of the 

 Orthoptera are remarkable for the apparent multiplicity of their 

 stomachs. The male cricket of gardens has four. This insect 

 and others analogous have been considered as ruminating insects, 

 or as having the faculty of returning again to their mouth the ali- 

 ments in their organs of digestion. But, according to Marcel 

 de Serres, these pouches or ccecums, which have been taken for 

 stomachs, are not so in reality, and contain only a salivary or 

 biliary fluid, which the animal disgorges when taken. Accord- 

 ing to Cuvier the crop of the Grylli forms often a lateral pouch, 

 and they have only two thick coecums at the pylorus, the biliary 

 vessels communicating with the intestine by a common canal. 

 The Locustce have also but two coacums, but the biliary ves- 

 sels surround the middle of the intestine and communicate with 

 it directly. The Forficulce or earwigs are the only Orthop- 

 tera in which the pylorus has no coecum. Five or six are found 

 in the crickets, and eight to ten in the Blattce. 



In insects, it is to be remarked, there often exist great differen- 

 ces in the structure of the intestinal canal, properly so called, in 

 the state of larvae and in the perfect insect. Thus, in the cater- 

 pillar of the butterfly there is an oesophagus dilated abruptly to 

 form a cylindrical stomach, with three transverse rows of coecums, 

 totally different from the form of the same parts in the per- 

 fect insect. Similar differences have been observed in the larva 

 of the bee, and indeed occurs in many groups. This change of 



