iC6 
NATURE NOTES 
Suppose an ant to be placed in the ultra-violet portion of 
a large spectrum — it moves away immediately. Does it move 
because it objects to the chemical rays which are transmitted so 
freely there, or because it objects to the colour of the ultra-violet 
rays, or because it is susceptible to the slight decrease in tempera- 
L.umifvoitB 
ture in this portion of the spectrum? It is probable that it is 
due to all these causes, yet, as far as I know, no experiments have 
been performed to show that ants are susceptible to very slight 
changes of temperature, such as would be experienced in the 
different portions of the spectrum. In order to prove this sus- 
ceptibility I performed the following experiments, which I have 
repeated at intervals with always the same result. '<jh«C“ 
The nests I used were constructed as follows : A sheet of 
glass lo ins. x 8 ins. formed the bottom of the nest. The top 
consisted of a similar but very thin piece of glass supported by 
strips of linoleum in. wide and \ in. thick. I hese strips 
were glued to the lower sheet of glass, thus leaving the upper 
piece free to be removed at will. A small opening was left at 
A, and the nest was placed on a board 2 ft. x i ft. 3 ins. 
with a small ditch of water round it. The space between the 
two pieces of glass was partly filled with fine earth, which the 
ants arranged after their own fashion. 
The following are the various experiments I performed with 
the time between them : — 
(i) September 21, 1904, a preliminary experiment. At 10.30 
a.m. I placed a glass cell 60 mm. square by 10 mm. deep on a 
