730 Sensibility to Light and Colour in [December, 
after a series of experiments upon various ova and larvae, 
found the adtion of the colours favourable in the following 
order : violet, blue, red, yellow, white, and green, the red 
and green rays being positively hurtful. We must confess 
that this summary of results obtained by M. Yung, and 
published in the “ Comptes Rendus ” of the French Academy 
of Sciences, seems to us deficient in intelligibility. If the 
red ray is ‘‘positively hurtful,” and if yellow and white 
lights are still less favourable to animal life it must, we 
think, naturally follow that they are hurtful also. It would 
therefore seem that further research in this direction is im- 
peratively demanded. 
The great sensitiveness of earth-worms both to different 
intensities and colours of light having been thus demon- 
strated, Prof. Graber undertook further experiments to test 
whether the entire skin of the worm is sensitive to light, or, 
as certain earlier observers have concluded, the anterior 
portion only. To this end similar series of experiments 
were undertaken with worms from which the anterior portion 
of the body had been removed. These experiments gave 
for light and darkness the quotient 2'6, and for red and blue 
2*8. These values are smaller than those obtained with 
entire worms, but they still permit us to conclude that the 
entire surface of these animals is sensitive to quantitative 
and qualitative differences of light. 
In view of the sensitiveness of the skin of eyeless animals 
it became desirable to ascertain the behaviour of the skin of 
blind animals towards light. For this purpose the sensi- 
tiveness of the salamander (it is here doubtful whether Prof. 
Graber refers to Salamandra maoulata , or, as would seem 
from an earlier passage, to Triton cristatus) to differences of 
light was examined, both in its normal state and when 
blind. Normal salamanders gave in eight enumerations, for 
the light compartment i, for the dark 159. With blind 
salamanders there appeared in eighteen enumerations, in 
the light cell 135, and in the dark 308. Hence it is legi- 
timately inferred that these animals, even without their eyes, 
are aware of great differences in the intensity of light. 
As regards qualitative differences of light, blind salaman- 
ders are also found to be sensitive. The behaviour of the 
normal salamander was first tested with light red and dark 
blue light. In ten enumerations there were found 192 in 
the former, and in the latter 8, the quotient being = 24. 
With blind salamanders Graber found 536 in the light red, 
and 406 in the dark blue, or a quotient of 1*3. It is there- 
fore not doubtful that the blind salamander, as well as that 
