CONSIDERATIONS. 131 



is the trunk, and, therefore, it usually contains the gizzard 

 ( ventriculus bulbosus), the sole expanded part of their ali- 

 mentary canal ; the intestine makes no convolutions in the 

 abdomen. In Arachnida and Insects the abdomen, on the 

 contrary, is the most voluminous part, and this contains the 

 principal expanded portions of the canal, though in Aranea 

 the ingluvies, or crop, is contained in the trunk. The intes- 

 tinal canal of carnivorous species, whether they feed on living 

 prey, on blood, or on decaying flesh, is uniformly shorter than 

 that of the herbivorous species, but these last are influenced by 

 the quality of their food, as leaves, fruit, honey, &c, which is 

 not the case with the former. 



The gizzard {ventriculus bulbosus) is the expansion most 

 constantly present, and where the crop is wanting is very 

 large. It mostly contains certain more or less complicated 

 masticatory organs, which appear to be analogous to the jaws 

 of Annelida ; they vary much in different genera. 



In the Staphylini, they consist of from five to ten, or even 

 more longitudinal ridges, placed in the circumference of the 

 gizzard, extending from the cardia to the pylorus. In Gryl- 

 lotalpa, &c, they are replaced by chains of small differently 

 formed pieces. These, as the longitudinal ridges, are sometimes 

 all similar, but more often alternately so. In many species 

 (Lepisma saccharina, &c), these ridges are each replaced by 

 a very hard angular piece. When the cardia and pylorus 

 are not diametrically opposed, these organs are found on one 

 side of its inner surface alone, as in Squilla mantis, or around 

 the cardia and pylorus, as in Cancer and Astacus. Some- 

 times they are altogether wanting. 



The name oesophagus is commonly given to that part of 

 the alimentary canal which extends from the pharynx to the 

 gizzard or stomach. In Man and Mammalia, a single name 

 suffices for this part; but in Annulosa and Annelida it is 

 distinguished into two or more parts, to which separate names 

 must be given, as has been done in Birds. Sometimes we find 

 a crop {ingluvies), as in Birds, opening laterally into the 

 oesophagus ; below this, a part of the oesophagus sometimes 

 performs the functions of the crop : this is the ventriculus, 

 which, in the herbivorous species, often occupies two-thirds of 

 the length of the alimentary canal. The name of oesophagus 

 should be confined to that part which conducts the food to the 



