APRIL 12, 1912] 
Dr. RicHarD DE ZreEuw publishes a helpful 
paper in the Centralblatt fiir Bacteriologie, 
Parasitenkunde und Infektionskrankheiten, 
1911, on the “ Comparative Viability of Seeds, 
Fungi and Bacteria when Subjected to Vari- 
ous Chemical Agents,’ in which he shows 
that the disinfection of seeds, etc., is by no 
means as easily accomplished as has been 
supposed, and that the results of many experi- 
ments requiring disinfection are open to 
criticism. 
WE can not pass by without at least brief 
mention the Journal of the College of Agri- 
culture of the Imperial University of Tokyo 
(Japan), in the December number of which 
are two articles by Professor Dr. S. Ku- 
sano, the first, on “ Gastrodia elata and its 
Symbiotic Association with Armillaria mel- 
lea,’ showing that this chlorophyll-less orchid 
lives in a beneficially symbiotic relation with 
the mycelium of the fungus. The second 
paper, “On the Root-Cotton, a Fibrous Cork 
Tissue of a Tropical Plant” (Fagara integri- 
folia), shows that “the root-cotton is a kind 
of cork tissue derived from the cork cambium, 
which arises primarily from the pericycle or 
secondarily from the bast of the root.” The 
author concludes that it is of economic value, 
“ chiefly in its unwettable and less hygroscopic 
quality.” The papers are illustrated by seven 
very fine plates. 
CHares E. Bessey 
THE UNIVERSITY OF NEBRASKA 
THE RELATION OF PIGMENTATION TO 
TEMPERATURE IN DEEP-SEA ANIMALS 
Proressor C. V. Burke’s article on the rela- 
tion of color of certain sea-animals to the 
depth at which they live’ is of much more than 
ordinary importance, for it may be possible to 
coordinate these facts with similar ones as to 
tropical land animals which show that pigmen- 
tation is of great, if not vital importance in 
heat regulation. In nearly all the biological 
literature on the subject, it is assumed that 
the sole use of pigment is for concealment by 
1 ScreNcE, October 6, 1911. 
SCIENCE 
591 
more or less resemblance to something in the 
background or to the background itself. This 
may be true of all colors but pigment of any 
color, if opaque enough, may protect under- 
lying tissues from death due to excessive light, 
a matter to which von Schmaedel first called 
attention as to man, nearly twenty years ago. 
This rule has now been found to be universal, 
for in every species there is a pigment or 
other protection proportionate to the inten- 
sity of the light. In the 1887 Proceedings of 
the Royal Society of Hdinburgh, Dr. Robert 
Wallace, now professor of agriculture in the 
University of Edinburgh, published another 
epoch-making observation, which, like that of 
Mendel and of many others, was completely 
ignored for a quarter century. Wallace found 
that all the domestic mammals of the tropics 
had black skins, and though Huxley was much 
impressed by the universality of the phe- 
nomenon, he could suggest no reason for it be- 
cause up to the time of his death very little 
was known as to the deadliness of the shorter 
ether waves to all naked living tissues, such 
as in the case of bacteria for instance; and 
though we then used sunlight to “ disinfect,” 
by killing our parasites, no one had yet per- 
ceived that it could also kill us. It is now 
known that the main purpose is light protec- 
tion, and there is a wealth of evidence that if 
unpigmented stock is taken from dark cli- 
mates to light ones it dies out. The agricul- 
tural experimenters have utterly failed to es- 
tablish the big white swine in our west or in 
any light climate and at the present moment, 
in many parts of the world, farmers are vainly 
trying to breed imported stock insufficiently 
pigmented. The matter is of such great prac- 
tical importance that it must be cleared up at 
once to stop the present wasteful methods. 
It has also long been known that black as- 
sists heat radiation in all temperatures below 
body heat. These black-skinned domestic ani- 
mals are then the fittest for tropical tempera- 
tures, but they can not expose themselves to 
the sun because of the fatal absorption of 
heat. They instinctively hide in the day, if 
the skin is not covered by a reflecting coat as 
in the Arab horse. In cold light countries 
