1897] Entomology. 727 
Generally a working ant only carries a single Antennophorus, but 
they may very often be seen carrying several. In all cases the para- 
sites take up positions symmetrical with the sagittal plane of their 
host’s body, and it thus comes about that the center of gravity of the 
extra load is placed in the sagittal plane of the carrying ant. 
The Acarids are also underjthe best conditions for not hampering 
the movements of the ants, and, as a consequence, for being the more 
readily tolerated by them. The Antennophorus directs its antenniform 
feet toward the front of the ant if fixed upon its head, and in the re- 
verse direction if fixed upon its abdomen. When an ant carries but 
one Antennophorus, it is almost always placed on the head of the host. 
The case of an ant carrying an Antennophorus under its head and one 
on either side of the abdomen is very common. The presence of one 
or more of the parasites on the body of a Lasius does not prevent the 
latter from taking its share in the work of the colony and in particular 
the carriage of the larve and rubbish. 
The Antennophorus attaches itself freely to the naked nymphs, but 
never to a nymph enveloped in a cocoon. Thus in an experimental 
nest consisting of some fifty ants, all carrying a single Antennophorus 
and accompanied by a certain number of nymphs, I found on the fol- 
lowing day a newly emerged ant which bore seven Antennophori ar- 
ranged symmetrically as follows: two (one on the top of the other) on 
either side of the head and on the abdomen, one on the middle of the 
dorsal region and one on either side. It would appear that the Anten- 
nophorus is attracted to the young ants on account of the care with 
which they are looked after and fed by their older. companions. These 
latter do not seek to drive away the parasites which spread themselves ~ 
a little later. At the moment when a queen throws off ber nymphal 
envelope the workers come to her assistance, and as the workers carry 
the Antennophori, these latter generally take advantage of the position 
to pass over to the body of the newly emerged queen. 
The Antennophorus feeds exclusively on the nutritive fluid disgorged 
by the ants. Fifty Lasii carrying Antennophori were placed in an ob- 
servation nest and left without food. Eight days later the ants were 
in perfect condition, but ten or more Antennophori had already died of 
hunger. A tiny droplet of honey tinted with Prussian blue was al- 
lowed to run over the lower face of the glass plate which formed the 
roof of the nest. A large number of ants, nearly every one of which 
carried an Antennophorus, ranged themselves as closely as they could 
be packed all around the drop. The Antennophori had no share in 
the meal, and they were obliged to retire a little because there was no 
