C46 DESCRIPTIONS OF PLATES. 



(original), marked as before. H is the internally longitudinally folded colon 

 to which the last segment of the larva is still attached. Fig. 2, Intestinal 

 canal of the perfect beetle (Suckow). D is the ventriculus, the anterior half 

 of which is covered with the pancreas, and the posterior portion, D*, with 

 glands. Fig. 3, Intestinal canal of the larva of Dyticus marginalis (orig.), 

 marked the same. Fig. 4, That of the perfect beetle, as before, the ventriculus 

 anteriorly covered with the pancreas. 



PI. XX. Fig. I, Intestinal canal of Cetonia aurata (Ramd.). D, The 

 pancreas covers the ventriculus with three coronets. F, The clavate gut. 

 Fig. 2, Ditto of the perfect insect (&.), as before. Fig. 3, Ditto of Cimex 

 rufipes (Trevir.). a a and /3 /3 are the setae of the proboscis whence the vessels 

 y y originate which open into the commencement of the ventriculus. b b, The 

 salivary vessels and glands. I), The first stomach with the two-folded bodies 

 (S S) at its orifice (this supplies the place of a crop). D*, The second stomach 

 (supplying the place of a proventriculus). D**, The third stomach, forming, 

 as it were, a second crop in front of the true ventriculus. D***, The ventri- 

 culus, consisting of four contiguous tubes. The rest as before. 



PI. XXI. Fig. 1, Intestinal canal of Gryllus migrator ius. Lateral view. 

 a a, Four of the six blind tubular appendages at the orifice of the stomach 

 (pancreas), n, Nervus syinpathicus. Fig. 2, The same opened. B, The 

 crop with the rows of teeth. **, Spot where the blind appendages open. 

 D, Ventriculus. ****, Spot where the biliary vessels open; the rest the 

 same as before. Fig. 3, a b, Two rows of teeth which are found within the 

 crop much magnified. Fig. 4, Raised longitudinal ridges beset with teeth 

 within the lower portion of the crop. Fig. 5, The processes, b b, of the internal 

 tunic of the stomach, a a, which thrust into the blind appendages and their 

 cavities, and open at C C into the intestine. Fig. 6, The portion of the intestine 

 where the blind appendages open, a a, their apertures ; these cut off, to show 

 their internal volume, c c, V-formed horny teeth, which form the proventriculus 

 Fig. 7, (Esophagus and crop of Gryllotalpa milgaris (J. Muller). A, (Eso- 

 phagns. B, Crop. C, Continuation of oesophagus. D, Proventriculus. 

 E E, Blind bags which open into the commencement of the ventriculus. 

 G, Ventriculus. a, Cerebrum, b 6, Nervous cords which form the first 

 ganglion, c, of the sympathic system. d d, The sympathic nerves. 

 c, Branch of it for the crop. /, Second or connecting ganglion. #, Branch 

 for the proventriculus. Fig. 8, Transverse section of the proventriculas of 

 Termes fatalis. a a, Projecting horny plates, b b b, Six fasciculi of muscles 

 which close it. Fig. 9, Lateral view, a, Space before the proventricalus, crop. 

 b, The proventriculus seen through the contracted orifice of the ventriculus. 

 </, Ventriculus. Fig. 10, Opened proventriculus of Termes fatatis. a a, Twelve 

 horny plates, which are alternately supplied with strong fasciculi of muscles, 



