THE INTERNAL ANATOMY OF INSECTS 



153 



insects and in the two sexes of the same species; but that of a male 

 mosquito will serv^e as an example illustrating its essential features. 



The following 

 account is 

 based on an in- 

 vestigation by 

 Professor Ch. 

 / M. Child ('94). 

 In an an- 

 tenna of a mos- 

 quito (Fig. 173) 

 the scape or 

 first segment, 

 which contains 

 the muscles of 

 the antenna, is 

 much smaller 

 than the pedicel 

 or second seg- 

 ment, and is 

 usually over- 

 looked, being 

 concealed b y 

 the large, glob- 

 ular pedicel; 

 the clavola con- 

 sists of thirteen 

 slender seg- 

 ments. Excepting one or two terminal segments, each segment of 

 the clavola bears a whorl of long, slender setae; these are more 

 prominent in the male than in the female. 



Figure 174 represents a longitudinal section of the base of an 

 antenna; in this the following parts are shown: S, scape; P, pedicel, 

 C, base of the first segment of the clavola; cp, conjunctival plate 

 connecting the pedicel with the first segment of the clavola; pr, 

 chitinous processes of the conjunctival plate; m, muscles of the 

 antenna; N, principal antennal nerve; n, nerve of the clavola; 

 immediately within the wall of the segments there is a thin layer 

 of hypodermis; the lumen of the pedicel is largely occupied by a" 

 ganglion composed of scolopophores, the attachment fibers of which 

 are attached to the chitinous proce'-ses of the conjunctival plate. 



Fig. 173. — Antennas of mosquitoes, Culex; 

 female; s, scape; p, pedicel. 



