ApRIL 12, 1912] 
sun, nor can sea-mammals absorb to any ex- 
tent that way as the heat does not penetrate 
enough. The surrounding medium is always 
below body temperature and the heat flow is 
always from the body not into it. As all mam- 
mals seem to depend upon more or less con- 
stant loss of superfluous heat by radiation and 
much loss during exertion, the black colors 
are probably of as great use to whales and 
porpoises, as to elephants and similar hairless 
tropical animals who likewise are never ex- 
posed to extremes and whose ranges of tem- 
perature do not differ markedly from those of 
the sea mammals. That is, there must be, as 
in horses, some means of preventing overheat- 
ing, and color surely helps according as the 
animal is shaded or exposed to the sun. The 
amazing differences in horses can be logically 
explained on these lines, as seen in the above 
paper. Hence there is a suspicion that dark 
color in all sea-fishes at any depth has some 
unknown relation to the temperature, as well 
as the need of concealment. It must be re- 
membered that the inner surfaces of shells, 
and the concealed surfaces of some parts of the 
bodies of many animals are most unaccount- 
ably pigmented. Neither the food nor protec- 
tion from light nor resemblance to the back- 
ground can be the reason, nor can it be a 
vestige of a previous useful condition. In- 
deed it is a puzzle which needs explanation, 
and it is requested that in all future studies 
there be facts presented as to the temperature 
of both the water and the body of the animal. 
It is not likely that the deep-sea fish can func- 
tion at such low temperatures as we are told 
do exist, and it is probable that we shall find 
that where life is abundant the temperature 
of both fish and water is considerably above 
40° but that in the vast areas where no life 
at all is found the cold may be the prohibitive 
factor. There must be as great variation 
from place to place by reason of currents as 
in the air. The prevalent winds make only a 
few degrees difference between the tempera- 
ture of the northeast and southwest of Japan, 
but the horses in the first place are dark brown 
and in the latter light yellow for this reason 
alone. There must be similar local differences 
SCIENCE 
593 
in the deep sea, due to currents to account 
most fully for differences in pigmentation. If 
the color darkens with increasing depth and 
coldness, then the animals surely lose by radia- 
tion what little heat they have and must be 
unable to function at all. Unless, then, there 
are different laws for the deep sea life, of 
which we can not conceive at present, there 
must be another reason for a concealing black- 
ness which would be a fatal radiator to ances- 
tral types nearer the surface. Indeed there 
may be some unknown laws of heat radiation 
under such tremendous pressures, which actu- 
ally reverse matters and make the pigment a 
conserver of body heat in cold water. It can 
searcely be believed that the color is to help 
absorption of heat, for there is little to be ab- 
sorbed—the animal must depend on its own 
heat production. That is, the facts so far 
known do not explain the blackness of the 
deep sea fish. 
Cuas. E. WoopruFF 
PHYSIOLOGICAL SEX DETERMINATION 
AN interesting, if not convincing, collation 
of arguments in support of the notion that the 
suprarenal capsules are concerned in deter- 
mining the sex of offspring was presented to 
the Paris Academy of Sciences on November 
20, 1911, by Dr. R. Robinson. His arguments 
fall into three groups. ° 
1. Clinical observations. 
It has been shown by Dr. Fieux Agregi, of 
Bordeaux, that when the heart-beat of the 
foetus is between 136 and 150 per minute there 
is born a female in 68 per cent. of the cases; 
if the heart-beat is more than 150 it is always 
a male. He had fifty cases. Robinson not 
only confirmed Agregi’s observations, but was 
able to determine the retarding action of the 
administration of adrenalin upon the pulse of 
the foetus. He therefore presumes that if this 
substance were administered from the early 
days of pregnancy it would influence the 
heart-beat and so the sex of the feetus. 
2. Anatomo-physiological facts. 
The adrenal glands seem to influence the 
development of the individual after birth, if 
they do not cause the determination of the 
