254 CLASS VIII 
the peritoneal covering of the intestines in vertebrate animals; 
next, a muscular coat of longitudinal and transverse fibres; then a 
white, smooth membrane, a layer of areolar tissue probably corre- 
sponding to the tunica propria of the intestine in vertebrates, but 
which is often beset with minute glands in transverse rows: and 
lastly the innermost membrane, an Epithelium, that occasionally, as 
in the muscular stomach of the Orthoptera, is found hard and horny, 
forming the teeth or sharp plates with which the stomach is armed. 
In the intestinal canal of Insects several parts are to be 
distinguished: but it is much to be wished that writers in the 
names given to them had been careful to preserve greater uni- 
formity. The first part is the cesophagus, it has often an expan- 
sion named erop (ingluvies); next follows a muscular stomach 
(ventriculus musculosus, der Kaumagen, le gésier, the gizzard) ; it is 
found in the Orthoptera and amongst the Coleoptera in the genera 
Staphylinus, Dytiscus, and the family of the Carabici’, and is 
remarkable for the great development of the innermost coat, for 
the projecting plates, teeth or hooklets of corneous tissue which 
serve for bruising the food; it is usually folded and has a round, 
more or less spherical; form*. Then comes a long cylindrical 
stomach in which the proper digestion proceeds. LEon Durour 
names it ventricule chylifique ; RAMDOHR calls it simply the sto- 
mach, which name appears to me to be sufficient and preferable to 
the other. This organ is always present, and beneath its termina- 
tion the vasa urinaria (of which hereafter) are always inserted®. 
To this succeeds a longer or shorter, sometimes (as in the Hemi- 
ptera) a very short canal, the small intestine (intestinum tenue), 
which is continued into the short large intestine (intest. crassum), 
having occasionally a cecum or expanded portion when the con- 
nexion takes place obliquely and at the side‘. 
1 Leon Durovur has also discovered a muscular stomach in Vomicus typographus. 
Ann. des Se. nat. IV. p. 108. 
2 RAMDOHR names it Faltenmagen (plicated stomach, omasus), a very ill-chosen name. 
3 MARCEL DE SERRES considered the stomach to be duodenum ; in that case many 
insects must have no stomach at all. The name of Crop (jabot succenturié) by which 
StRAvUS denotes this part in the Cockchafer is not explicable. 
4 We are indebted to Lion Durour for most of the investigations of the intes- 
tinal canal in Insects. They were preceded by those of RaMpDOoHR, who published a 
work on the subject, (Abhandlungen iiber die Verdauungswerkzeuge der Insecten, mit 
30 Kupfertafeln, Halle, 1811, 4to). 
