XXXIV INTKODUCTIOTf. 



which uot only treats the whole subject iti detail, but gives very 

 full bibliographical references under each section. So much has 

 been copied on this matter by one writer from another (original 

 investigation requiring skilful and delicate manipulation combined 

 with a thorough physiological training) that we can only sammarize 

 the most condensed information. The number of entomologists 

 who study this branch of the science is to-day infinitesimal, in 

 fact anatomy is almost entirely neglected. According to Sharp: 

 "The alimentary canal presents considerable diversity and some 

 remarkable features. There is a slender tube-like oesophagus and 

 a lai'ge crop. It is difficult to assign any of the parts posterior to 

 this to the divisions usual in other insects, and it is said that the 

 distinction of parts histologically is as vague as it is anatomically.'^ 

 (Cambridge Nat. Hist. vi. p. 540.) Packard describes the «eso- 

 phagus as " usually small and short, while the much convoluted 

 stomach is very long and subdivided, first into a large, straight, 

 glandular portion ; second, into the convoluted smaller part ; and 

 third, in some Pentatomids and Coreids there is a third stomach,"' 

 which, quoting Siebold, he describes as " consisting of a very 

 narrow, slightly flexuous canal, on which are inserted two or four 

 rows of closely aggregated glandular tubes" (' Guide to Study of 

 Insects,' p. 517). There is no gizzard ; the number of Malpighian 

 tubes is usually four, one pair only being found in Coccid^e, and none 

 in Aphidse. Packard describes the nervous system as consisting, 

 besides that of the head, of two thoracic ganglia, of which the 

 anterior is the SBialler, which send off two main trunks to 

 the abdomen. " In Pentatoma all the three ganglionic masses are 

 brought into close proximity, but in Nepa the thoracic mass of 

 ganglia and the infra-oesophageal ganglion are widely separated "^ 

 (Sharp). 



In the reproductive system the Ehynchota exhibit some 

 peculiarities in the testes, and according to Packard the number 

 of testicular tubes is small in most members of the Order, but 

 very gi-eat in the Cicadidse, as in Orthoptera, Coleoptera, and many 

 Hymenoptera (' Text-book of Entomology,' p. 495). 



Reference has already been made to the metamorphosis or post- 

 embryonic development of the Ehynchota, as being a development 

 in which the young differs but little from the adult. This is quite 

 true in a general \\'ay, but it is not a precise statement, ae the 

 immature forms have a general and apparent, but not exact, resem- 

 blance to the perfect insect. jS'o inconsiderable service would be 

 rendered to entomology, if some of our readers in India would 

 undertake the investigation of this subject, carefully describing and 

 drawing the various modifications in metamorphosis from the first 

 to the adult stage, with a record as to the exact period occupied 

 in each stage of development. 



The field collector of Ehynchota will soon acquire a more 

 perfect acquaintance with the habits of these insects than can be 

 derived from the perusal of entomological books. Many small 



