188 
revised in order to accord with our present 
knowledge of this form. We will note the fol- 
lowing: The “liver” is now known to be 
both a digestive and absorbent organ, the 
finer particles of food being delivered to it 
directly from the pyloric end of the stomach- 
sac. The idea that when a “limb is cast off,” 
the opening at the breaking plane becomes 
closed by a clot of blood, and that further 
bleeding is thus stopped, had been proved by 
Emmel to be an error; the stoppage is effected 
by definite valves, without which the animal 
would doubtless bleed to death. 
A third species of lobster (Homarus capen- 
sis) is attributed to the Cape of Good Hope. 
We were under the impression that this 
shadowy species had never recovered from the 
aspersions cast upon it by Professor Huxley. 
Regarding the relation of the young crayfish 
to its mother (p. 77) many new facts have 
been brought to light by the studies of An- 
drews for both Astacus and Cambarus. 
In discussing the phosphorescence of deep- 
sea crustacea (p. 126) it is noticed that many 
luminous forms are blind, but that in such 
eases luminous secretions are emitted from 
the skin without the aid of specially differen- 
tiated organs, the photophores, the complete 
meaning of which is puzzling, not to say em- 
barrassing, as in certain prawns which illumi- 
nate their gill-chambers. We are reminded 
of a similar trouble regarding the ubiquitous 
tegumental glands, which occur among other 
places in the labrum, swimmerets, statocysts, 
the intestine and the gills. It might be 
interesting to inquire whether there is any 
relation between these organs and such parts 
of the skin as are responsible for the secre- 
tions referred to above. In another place it 
stated that while many deep-sea species are 
some tint of red, their eggs are blue or green. 
If these forms were originally emigrants from 
shallow water, the colors of the eggs would ap- 
pear to have remained stable notwithstanding 
the change in the color and habits of the 
adult, a condition which is paralleled in cer- 
tain birds like the magpie, wherein the 
mottled coloring of the egg is evidently older 
than the habit of covering the nest. 
SCIENCE 
[N.S. Vou. XXXV. No. 892 
The author suggests that the exceedingly 
long, attenuated, and often hirsute character 
of the appendages of deep-sea erustacea may 
be an adaptation to prevent the animal from 
sinking in the ooze; we should rather regard 
such conditions as aids to the animals for 
feeling their way in the darkness, in other 
words, as means for increasing their explora- 
tory powers, and for rendering the chemical 
sense and that of touch more effective. 
Regarding the question of metamorphosis 
among crustacea of the abyss Dr. Calman re- 
marks: “It would seem that, some way or 
other, the conditions were unfavorable for a 
free-swimming larval life; but they can not 
be altogether prohibitive, for many deep-sea 
crustacea have small eggs, and presumably a 
metamorphosis.” There is certainly no doubt 
that such species with small eggs undergo a 
metamorphosis, but it does not follow that the 
young ascend a mile or more to the surface in 
order to accomplish it. Such young may per- 
tain exclusively to the hypoplankton and keep 
near the bottom, or to the mesoplankton in 
strata not far above it. Jt would be interest- 
ing to know to what extent larve like those of 
lobsters and crabs which keep for a time at 
least near the surface, and belong to the epi- 
plankton, can adapt themselves to the changes 
in pressure involved in falling through meas- 
ured distances in the water. Experiments to 
settle this point could be made without great 
difficulty. ; 
The author thus speaks of the various ani- 
mals which form the floating population of 
the Sargassum: “All of them are colored 
olive-green, like the weed among which they 
live.” Now the Sargassum which we have 
repeatedly encountered in the Gulf Stream in 
going to or from the West Indies was always 
a beautiful golden brown tint, flecked with 
white, the light spots being due to bryozoa 
which commonly encrust the floats of this 
plant. Moreover, the entire population—fsh 
(Pterophryne), shrimp and a nudibranch mol- 
lusk—wore the same colors, and usually in 
the same simple pattern, brown with oblitera- 
tive white spots. 
