128 ANATOMY. 



ance, and is compact, opaque, and more distinctly muscular than the 

 rest of the intestinal canal. It consequently answers to the gizzard of 

 the gallinaceous birds, an analogy which still 'more strongly confirms 

 the general analogy of organisation existing between insects and birds. 

 A closer anatomical investigation of this organ displays two very 

 distinctly-separated membranes, the exterior of which is tight and 

 muscular, and the interior folded, smooth, and partially horny. The 

 folds of the inner membrane are by no means accidental, but perfectly 

 regular and differently formed in the several families. In the preda- 

 ceous beetles (Cidndelacea and Carabodea, Pi. XVII. f. 8), four is the 

 prevalent number. Four large arched folds, densely covered with short 

 horny spines, bend inwardly in the cavity of the organ, and between 

 these lie four smaller ones, which are sharply ridged in front. Within 

 the large folds there are four robust bundles of muscles, which unite 

 above and below, and thus form a closing muscle at each opening. The 

 similarly constructed mouth of the stomach in Stapkylinus has five 

 large folds and as many small ones. In Cryptorhynchus Lapathi there 

 are nine equal prismatic folds, from the inner ridges of which originate 

 two rows of diverging horny processes, which meeting from fold to 

 fold, separate a central star-shaped space from the entire cavity *. In 

 the Capricorn beetles (Cerambycma) there is no cavity at all, but at 

 the inner margin of the cardia there are four large and four smaller 

 horny plates (PI. XXII. f. ], Lamia cedilis}. The Ortkoptera (for 

 example, Acheta,) have six chief plates, which are covered with scale- 

 shaped horny plates. In the Termites (PI. XXI. f. 8 10.) I disco- 

 vered a proventriculus, which consisted of a ring of twelve equal broad 

 folds, between which again twelve finer and sharp edged ones lay. 

 Around this ring, which formed the central girdle of the cavity of the 

 organ, there were six strong fasciculi of muscles, which united above 

 and below like the ribs of a gothic arch, and thus formed closing 

 muscles. In Blatta, instead of folds we find hooked horny teeth, 

 which spring from a broad base at the sides of the stomach, and 

 project into its cavity. In Gryllus migralorius (PI. XXI. f. 1 6.) 

 I found no proventriculus, but the entire pharynx and crop were 

 armed with rows of small but differently sized teeth, which, running 

 longitudinally, formed in the centre transverse waved lines, but 

 towards the cardia again stand in twos and threes upon elevated mus- 



* Ramdohr, PI. X. f. 14. 



