884 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



believed it to be an apparatus for affording additional 

 support to the body. By BourletJ it was thought to 

 serve to moisten the springing organ as well as 

 serving as an adhesive organ on which the creature 

 might alight after springing, thus lessening the effect 

 of the shock of that movement. Reuter (22) looked 

 upon it as being a kind of hydrostatic organ. 

 He believed that the claws of the feet collected moisture 

 from the hairs of the general surface of the body 

 and conveyed it to the ventral tube, which served to 

 absorb it into the system. Sommer (23) believed it to be 

 an adhesive organ, and suggested that it also performed the 

 same service for the integument as does the preen gland 

 for the feathers in Birds. Schott (93) maintained a 

 somewhat similar opinion. 



The view which has received the widest support is 

 the one which regards the ventral tube as being an 

 adhesive organ enabling the insects to walk over smooth 

 or steep surfaces. This opinion is upheld by Bourlet (in 

 part), de Olfers (19) and Tullberg (96), who believed 

 that its power of adhesion was brought about by 

 means of suction. De Geer*, Nicolett and Lubbock, 

 however, thought that the adhesive function was effected 

 by means of a special secretion of the tube itself. Lubbock, 

 who studied the action of the organ in Sminthurus, where 

 it attains its greatest development, remarks that if one of 

 these animals be laid on its back, and a piece of glass be 

 brought within its reach, it will endeavour to seize it with 

 the feet, but at the same time it will protrude one or both 

 of the vesicles, emitting as it does so a minute drop of 

 fluid, which, no doubt, enables it to obtain a better hold. 



{ Mem. Soc. d'Agric. du department du Nord, 1841. 



* Abhandlungen zur Gescliichte der Insekteii, Bd. vii., 1783. 



f Reclierches pour servir d Vhistoire naturelle des Podurelles, 1841. 



