74 Psyche [April 
“This summer I have used a style of artificial nest which is excel- 
lently adapted for experiments on a small or very small scale, e. g. 
for making observations on single fertilized queens while they are 
founding their colonies. ‘These nests have, moreover, the advantage 
of being extremely cheap and easy of construction. 
“T make these nests from hollow tiles, such as are used in building 
light walls. These tiles, which are perforated with holes, are sawed, 
at right angles to the holes, into plates of the required thickness. 
Since the saw is soon blunted by this operation, I use an old one that 
is more or less worn. 
“Then I have each plate ground down till it is smooth on both sides. 
On one of these sides, which is to become the floor of the nest, I fill 
in the openings with plaster of Paris, and the other side is covered 
with a glass plate of suitable dimensions. ‘The cavities can then 
either be left as so many separate chambers or connected with one 
another by means of grooves, or even have one of their walls per- 
forated with a glass tube to serve as a communication with some other 
piece of apparatus. One of the chambers can be used as a water 
reservoir (as in the Janet nests) and remain isolated while the others 
are made to communicate with one another by means of grooves. 
‘““A convenient method of supplying these nests with the requisite 
amount of moisture is to place them on a layer of damp moss. 
“Plates of hollow tiling may also be conveniently employed as por- 
ous and quickly drying bases for ordinary Janet nests, as their lower 
surfaces are thereby prevented from becoming mouldy.” 
A small artificial nest of still a different pattern is employed by 
Dr. F. Santschi of Kairouan, Tunis, in his studies on colonies of 
diminutive ants which have to be kept in very tight receptacles. He 
described its construction to me in the course of a conversation, which 
I had with him in Lausanne during the past summer, as follows: 
The base of the nest consists of a rectangular glass plate, such as 
is most conveniently obtained by cleaning an unsuccessfully exposed 
photographic plate of ordinary dimensions, say 3 X 4 or 4 5 inches. 
Wet plaster of Paris is poured onto this plate in the form of the heavy 
lines in the accompanying diagrams, which represent nests with two 
and three chambers respectively, connected by galleries. Of course, 
any other design which suggests itself as suitable, may be used instead, 
if desired. Before the plaster has set, a second glass plate of the 
same size and shape as the base and previously covered with a film 
