122 
SIR JOHN LUBBOCK ON ANTS, BEES, AND WASPS. 
that he only suggests this explanation. The facts he mentions 
are very interesting, and it is to he hoped that he will continue 
his observations. 
On the Colour-sense oe Ants. 
Prof. Graber* lias published an interesting memoir on this 
subject. He confirms my observations on ants and Daphnias, in 
which I showed that they are sensitive to the ultra-violet rays, 
by similar observations on earthworms, newts, &c. It is inter- 
esting, moreover, that the species examined by him showed 
themselves, like the ants, especially sensitive to the blue, violet, 
and ultra-violet rays. Prof. Graber, however, states that he 
differs from me, inasmuch as I attributed the sensitiveness to the 
ultra-violet rays exclusively to vision ; that it is “ aussc-hliesslich 
durch die Augen vermittelt.” I would not, however, express that 
opinion as applying absolutely to all animals, though it is, I 
believe, true of ants, where the opacity of the chitine renders it 
unlikely that the light would be perceived except by the medium 
of the eyes and ocelli. 
Graber has demonstrated in earthworms and newts, and Plateau 
in certain Myriapodsf, that these animals perceive the difference 
between light and darkness by the general surface of the skin. 
But more than this, Graber appears to have demonstrated that 
earthworms and newts distinguish not only between light of 
different intensities, but also between rays of different wave- 
lengths, preferring red to blue or green and green to blue. He 
found, moreover, as I did, that they are sensitive to the ultra- 
violet rays. Earthworms, of course, have no eyes, but thinking 
that the light might perhaps act directly on the cephalic ganglia, 
Graber decapitated a certain number, and found that the light 
still acted on them in the same manner, though the differences 
were not so marked. He also covered over the eyes of newts, 
and found that the same held good with them. Heuce he con- 
cludes that the general surface of the skin is sensitive to light. 
These results are certainly curious and interesting ; but, 
even if we admit the absolute correctness of his deductions, 
1 do not see that they are in opposition to those at which 
I had arrived. My main conclusions were that ants, Daphnias, 
* “ Fundamental Yersuclie liber die Ilelligkeits- und Farben Empfindlieb- 
keit augenloser und geblendeter Thiere,” Sitz. Ivais. Akad. der Wiss. Wien, 1883. 
t Journ. de i’Anatomie et de la Physiologic, 1886, p. 131. 
