126 ANATOMY. 



fluids in the proboscis and oesophagus. Insects which chew are natu- 

 rally deficient in this apparatus, or at least in this function of it ; in 

 them it is a true crop. 



In the Hymenoptera (PI. XVII. f. 10, c,) the sucking stomach is a 

 distension of the oesophagus in front of the cardia, and consequently 

 perfectly resembles a true crop. Indeed, in those families of this order, 

 which possess more a mandibulate apparatus than a suctorial, this suck- 

 ing stomach must gradually become superfluous ; and it is, consequently, 

 so little distinct from the oesophagus that it was formerly always 

 described with it, and as nodose *. It exists however as a distinctly 

 denned organ in the families of the bees and wasps, which possess a 

 true suctorial apparatus ; and here it is a large bag, which hangs below 

 the oesophagus, in front of the mouth of the stomach f. If it be empty 

 it lies folded longitudinally ; when filled with air it is distended as a 

 transparent bladder, and embraces the long funnel-shaped mouth of 

 the stomach, which is furnished at its aperture with valves. 



In the Lepidoptera (PL XVIII. f. 5.) we find the sucking stomach 

 still more distinctly separated from the oesophagus. In these it projects 

 with a short neck at right angles from the end of the oesophagus, and 

 when simple it lies as a folded bladder contiguous to and over the 

 stomach, or upon each side of it when, as in Zyg&na J, it consists of 

 two equal halves. This division is sometimes unequal, when a smaller 

 bladder hangs beneath the large one . It is always proportionate in 

 compass to the length of the proboscis, so that it completely vanishes 

 when the proboscis dwindles to a short cone, as in Gastrophaga pint 

 and Cossus ligniperda ||. 



Many Neuroptera, for example, the genera Hemerobius and Phry- 

 ganea, have apparently similar bags, which are likewise inactively 

 folded, but which also admit, like those of the Lepidoptera, of being 

 distended into tight bladders. These organs may possibly be sucking 

 stomachs, particularly as these insects, although provided with a man- 

 dibulate apparatus, take food more by suction (this is the case espe- 

 cially in Phryganea) than by mastication. 



* For example, in the Tenthredos and Ichneumons, Ramdohr, PL XIII. f. 2 and 3. 

 and PI. XIV. f. 2. 



f Ramdohr, PL XII. f. 6. PL XIII. f. 1. PL XIV. f. 3. Treviranus, PL XIV. f. 3. 

 and PL XVI. f. 3. 



* Ramdohr, PL XVIII. f. 1. 



Trevirauus, PL IX.v,v II Ib. p. 109. 



