32 
ANIMAL INTELLIGENCE. 
following results. The ants which he observed greatly 
dislike the presence of light within their nests, hurrying 
about in search of the darkest corners when light is ad- 
mitted. The experiments showed that the dislike is much 
grsater in the case of some colours than in that of others. 
Thus under a slip of red glass there were congregated on 
one occasion 890 ants, under green 544, under yellow 495, 
and under violet only 5. To our eyes the violet is as opaque 
as the red, more so than the green, and much more so 
than the yellow. Yet, as the numbers show, the ants had 
scarcely any tendency to congregate under it : there were 
nearly as many under the same area of the uncovered 
portion of the nest as under that shaded by the violet 
glass. It is curious that the coloured glasses appear to act 
on the ants in a graduated series, which corresponds with 
the order of their influence on a photographic plate. Ex- 
periments were therefore made to test whether it might 
not be the actinic rays that were so particularly distasteful 
to the ants ; but with negative results. Placing violet 
glass above red produces the same effect as red glass 
alone. Obviously, therefore, the ants avoid the violet 
glass because they dislike the rays which it transmits, 
and do not prefer the other colours because they like the 
rays which they transmit. Sodium, barium, strontium, 
and lithium flames were also tried, but not with so much 
effect as the coloured glass. 
It has just been observed that the relative dislike which 
Sir John Lubbock’s ants showed to lights of different colours 
seems to be determined by the position of the colour in 
the spectrum— there being a regular gradation of intole- 
rance shown from the red to the violet end. As these ants 
dislike light, the question suggests itself that the reason 
of their graduated intolerance to light of different colours 
may be due to their eyes not being so much affected by 
the rays of low as by those of high refrangibility. In this 
connection it would be interesting to ascertain whether 
ants of the genus Atta show a similarly graduated intole- 
rance to the light in different parts of the spectrum ; for 
both Moggridge and MacCook record of this genus that it 
not only does not shun the light, but seeks it — coming to 
