ANATOMY AND PHYSIOLOGY 35 
be adapted for other than sensory functions. Thus the anten- 
nee of the aquatic beetle Hydrophilus are used in connection 
with respiration and those 
of the male Meloe to hold 
the female. 
i 
pad | 
Sexual Differences in An- 3 
tenne.—In moths of the Wy, 
family Saturniidze (S. cecro- “ 
pia, C. promethea, etc.) the WV 
pectinate antennz of the male = 
are larger and more feathered SH 
than those of the female, =e 
and differ also in having more : 
segments (Fig. 42). Here is: 
the antennz are chiefly olfac- = 
tory, and the reason for their 
greater development in the Antenne of a moth, Samia cecropia. A, 
male appears from the fact Pos sega 
that the male seeks out the female by means of the sense of 
smell and depends upon his antennz to perceive the odor ema- 
nating from the opposite sex. 
The plumose antennz of the male mosquito (Fig. 43) are 
highly developed organs of hearing, and are used to locate the 
female; they have delicate fibrillae of various lengths, some of 
which are thrown into sympathetic vibration by the note of 
tie female (p. 107). 
Meloe has just been mentioned. In Sminthurus malmgrenit 
(Collembola) the antennz of the male are provided with 
hooks and otherwise adapted to grasp those of the female at 
copulation. 
Though systematists have recorded many instances of an- 
tennal antigeny, the interpretation of these sexual differences 
has received very little attention; though a beginning in the 
subject has been made by Schenk, whose results will be re- 
ferred to in connection with the sense organs. 
Mouth Parts.—On account of their great range of diffe- 
