& 
1887] Entomology. | 285 
can only be determined by means of sate experiments ; 
they pad receive taste-nerve termin 
e pe furnished vay tae pear for histologi- 
between thirteen thousand and fourteen thousand olfactory pits 
and about seven hundred teeth (Kegel). Fig. 6 represents a 
cross-section through the penultimate antemi joint of Vespa 
crabro; we can see how thick are the series of openings on the 
surface of the antennæ, and how regular is the distribution of 
the teeth. 
The distribution of the olfactory pits and olfactory teeth is 
thus seen to be very general; the deviations are so insignificant 
that there is no reason for the establishment of more than one 
X 
A earal pits with a small crevice-like opening occur in genera 
etA allied to Vespa and also in most Ichneumonidæ, Braconidæ, 
sand Cynipidæ. But the crevice- sais openings in these families 
are Eoasidershly longer and often are of a somewhat twisted 
shape. In all the species with Hansard antennz we can recog- 
pits of Apis mellifica, as well as those of Bombus and allied 
genera, differ from those T the Ichneumonidz in being not like 
crevices, but circular open 
The distribution ‘of the scsi peg or tooth-like projections 
(Kegel) seems to be much more limited than that of the pits in 
the Ichneumonide. Hauser could not find any. Apis mellifica 
possesses on each antennal joint only about twenty slender pale 
teeth, scarcely a third as many as in Vespa crabro; on the other 
hand Formica, of which genus several species were examined, 
seems to have far more teeth than pits ; they are relatively long, 
openings, which led into a bottle-shaped invagination of the in- 
tegument and contained an olfactory style. In the Tenthre- 
dinidz only teeth and no pits were to be detected. Sirex has on 
the under side of the nine last joints of each antenna a group of 
from two hundred to three hundred small teeth, which resemble 
those of Vespa sig Lyda has on the terminal joints: about 
one hundred teeth 
The author then discusses these facts from the Darwinian 
