390 DR. J. B. HICKS ON THE ORGANS 
are few and long; whilst the apex, which has three spinous processes which are supplied 
with a nerve, doubtless possesses the sensation of touch (see M. figs. 1, 2, 3). 
In Meloe the antennæ consist of eleven joints, of which the 1st, 2nd, 3rd, and 9th are 
not furnished with the organs, as all the rest are, especially the 6th, 7th, 10th and 11th: 
those in the last, or 11th, are the largest. They have the same form as those of the Neero- 
phora Vi espillo, but rather smaller. 
In Clytus arcuatus the sacs are found interspersed between the hairs, of the diameter 
of 305 inch, in considerable number on the last five joints, and of the same form as in 
Necrophora Vespillo. 
I shall next describe the antennæ of the Hymenoptera. 
In the genus Vespa, whose antenna I have described in my former paper, I have since 
had an opportunity of examining the antenna of the male, female, and neuter, both of 
V. vulgaris and also V. Crabro. In all these, as there described, the last ten joints are 
covered on all sides from base to apex by organs having the canoe-shaped closing-in mem- 
brane. The number of these on each antenna of F. vulgaris is prodigious; on each seg- 
ment there are rather more than 2000. The 3rd segment possesses rather fewer, and the 
12th rather more, making altogether on the ten segments 20,000 for each antenna. There 
are also on this antenna many dwarfed hairs, as on that of Dyticus marginalis. There is 
no particular difference between the different sexes and neuters; and I may add that å 
distinet sac is visible behind the oval opening, which is seen behind the canoe-shaped 
closing-in membrane. | 
In Apis mellifica, however, the antenna of the worker or neuter (described in my 
former paper) possesses the organs only on one side; whilst in the drone or male the 
antenna is entirely covered with them, similar to those of the male Æucerus longicornis 
(see former paper, Pl. 30. fig. 7). I have, unfortunately, not succeeded in obtaining a 
female or queen, to enable me to institute a comparison: still one would argue that if 
these organs were olfactory, we ought to find them in a peculiar degree developed in the 
worker, and scanty in the male, who seldom leaves the hive, and then only for a short 
distance; but the contrary is the case. | 
Odynerus murarius possesses organs very like those of the neuter Apis mellifica, situated 
, on one side; and as the other side is free from any markings, the nerve and its distribu- 
tion and the accompanying tracheæ can be beautifully seen. The nerve, accompanied by 
two tracheæ, passes from base to apex, through the centre, giving off a branch from 
either side, about the centre of each segment, which branch passes through the next joint, 
to be distributed to the organs in the succeeding segment, and again giving off numerous 
fibres to supply the organs with sensation. i 
A remarkable antenna among the Hymenoptera is that of the Red Ant, Myrmica rubra. 
. It consists of twelve segments 
right angle; the segments after the second gradually increase in width to the last, which 
is longer than any, except the first, and tapers gradually to a point, towards which the 
antenna-wall gradually becomes thinner, so that at the extreme apex it is very delicate, 
the hairs also abbreviated. The surface is furnished tolerably thick with hairs, as in most 
antennæ. It also possesses the sacs very well marked, as may be seen at N. fig. 1 4 34,4 
: the first is very elongated, the rest being joined to it ata — 
