NO. 



MORPHOLOGY OF INSECT SENSE ORGANS SNODGRASS 



beyond the base of the hair. The process has a subterminal swelhng 

 (a) which contains a dark nucleus-hke body. Whether this body be- 

 longs to the cell process, or is a nucleus of the neurilemma investing 

 the latter was not determined, but Schneider points out that the 

 swelling is not the sense cell of the organ, though some writers have 

 described it as such. 



Other writers, Viallanes (1882), Monti (1893, 1894), Hilton 

 (1902), Zawarzin (1912 a), and Orlov (1924), have given essen- 

 tially the same account of the subhypodermal sense cells in larval 

 insects, but with less detail as to the structure of the sense organs 

 with which they are connected. 



Fig. 12. — Example of a tactile hair innervated through an intrahypo- 

 dermal sense cell. (Section of a hair on the cercus of an adult cricket, 

 Gryllus campestris, diagrammatic from Sihler, 1924.) 



Sensory hairs zmth intrahypodermal sense cells. — The structure 

 of a hair sense organ in which the sense cell lies within the normal 

 hypodermis may be illustrated by an example taken from the work 

 of Sihler (1924) on the sense organs of the cerci of a cricket {Gryl- 

 lus campestris). 



The long hairs on the cerci of the cricket are set into deep cup-like 

 alveoli (fig. 12, Alv). The lips of each cup project above the surface 

 of the surrounding cuticula as a circular rim, while a horizontal 

 chitinous ring projects from the inner walls of the cup to brace the 

 base of the hair. The hair in these organs is rather solidly inserted 

 into the bottom of the cup and the usual articular membrane is lack- 

 ing. Beneath the hair is a large trichogenous cell (HrCl), with a 

 basal nucleus and its central part occupied by a vacuole (Vac) con- 



