100 EN TOMOLOGY 
insect perceives some odors by means of the antenne and 
Fic. 132. others by the palpi or other 
organs. Hauser found that 
the flies Sarcophaga and Cal- 
liphora, after the amputation 
of their antennz, became 
quite indifferent toward de- 
cayed meat, to which they 
had previously swarmed with 
il ) 
ALN 
great persistence, though 
their actions in all other re- 
Pee ee ee Ne» Spects remained normal. 
pit with peg; pb, protecting bristles; Males of many moths and a 
s, sensory cell.—After Hauser. is 
few beetles are unable to find 
the females (see beyond) when the for- 
mer are deprived of the use of their 
antenne. 
End-Organs.—Structures which are 
regarded as olfactory end-organs occur 
commonly on the antennz, often on the 
maxillary and labial palpi and sometimes 
on the cerci. These end-organs are hy- 
podermal in origin and consist, generally 
speaking, of a multinucleate cell (Fig. 
131) penetrated by a nerve and prolonged 
into a chitinous bristle or peg, which is 
more or less enclosed in a pit, as in Ta- 
banus (Fig. 132). In many instances, 
however, the end-organs take the form of 
teeth or cones projecting from the gen- Longitudinal section 
eral surface of the antenna, as in Vespa ee ee 
(Fig. 133). These cones are usually less ¢ olfactory cell; cn, ol- 
numerous than the pits; in l’espa crabro, as ee ere 
for example, the teeth number 700 and hy ie ari 
the pits from 13,000 to 14,000 on each 
antenna. ‘The pits are even more numerous in some other 
