The Anatomy of Ants. By Sir John Lubbock, Bart. 141 
Fig. 2, p m 7 and 8) longitudinally along the upper wall of the 
pharynx, while the others run at right angles to the first, across 
the upper wall of the pharynx (Plate CXCI., Fig. 2, p m 9 and 10). 
Lastly, there is a single retractor (Plate CLXXXIX., Figs. 1 and 
3, p m 11) which is attached to the hinder wall of the pharynx, and 
passing just over the mouth sac, contracts into a long tendon, 
which is attached to the end of a short median process of the 
transverse bar which supports the two antero-posterior processes. 
The walls of the pharynx are more or less chitinous, and the 
lower portion immediately above the entrance to the mouth sac is 
covered with small teeth, which point downwards. This arrange- 
ment is unusual, since in most animals the palatal teeth point 
backwards, so as to prevent any food which has once entered from 
returning ; and, on the contrary, to promote its passage down the 
throat. I presume, however, that in ants, which feed principally 
on animal and vegetable juices, it is advantageous to prevent the 
entrance of solid particles. 
After arriving opposite the antennas the pharynx arches round 
and passes into the oesophagus, which then passes directly through 
the back part of the head, between the great cephalic ganglia, 
through the thorax, and the constricted portion of the abdomen. 
Leon Dufour, indeed, described the front part of the pylorus as 
lying in the petiole, but, like Meinert, I have found it in all the 
species which I have examined in the swollen portion of the 
abdomen. 
Shortly before reaching the great cephalic nervous mass, the 
oesophagus receives a muscle (Plate CLXXXIX., Fig. 1, oe m 1) 
which descends upon it from the upper surface of the head, some 
little distance in advance of the central ocellus. A little farther 
back it receives also the anterior ends of three retractor muscles. 
One of these passes backwards, and is attached just above the pos- 
terior end of the retractor of the pharynx to the median process 
of the crossbar connecting the antero-posterior processes. Plate 
CLXXXIX., Fig. 1, a? 2. 
The other two (Plate CXC., Fig. 2, oe m 3) are attached, one on 
each side, to the upper posterior wall of the head, whence they pass 
straight forward, and are attached to the sides of the oesophagus. 
The principal salivary glands are six in number. The largest 
ones are situated in the upper and anterior part of the thorax. 
They consist of a number of branched and twisted tubules, which 
gradually unite into a single duct. This duct then swells into 
a capacious receptacle, after which it contracts again, and, after 
joining the corresponding duct from the other side, passes through 
the neck into the head, and then after a meandering course, as 
shown in Plate CLXXXIX., Figs. 1-3, D S, opens at the upper 
