May 31, 1901.] 
partially suspended in a layer of soup-like 
consistency and character. Bathybius, then, 
is now no longer known as Bathybius, but 
as ‘ bottom broth,’ an exceedingly suggestive 
term, and it is supposed to be the inexhaus- 
tible supply of nourishment, the basal food 
store-house of the innumerable creatures 
that live and move, or simply live without 
movement, at or near the bottom of the sea, 
the simplest and most helpless of which 
have but to open their mouths, if mouths 
they have, and suck in bottom broth as the 
infant does pap. If Old Ocean is really, as 
so often asserted, the mother of terrestrial 
life, then bottom broth can truly be re- 
garded as a sort of mother’s milk, for the 
nourishing of her weak and helpless off- 
spring. 
Having discussed the physical conditions 
under which the animals of the deep sea 
exist, let us now turn our attention to the 
animals themselves. 
Personally, I may say that nothing re- 
garding the animals dredged from deep 
water has impressed me more than their 
colors. It seems an unquestionable fact 
that they live in practical darkness, and 
one naturally expects them to be colorless. 
Now we know of a considerable number 
of animal forms that certainly do live in 
utter darkness in the subterranean waters 
_of extensive caves, such as Mammoth or 
Wyandotte Caves. These animals have 
been very carefully studied, especially by 
my friend Dr. Higenmann, of Indiana Uni- 
versity, who tells me that true cave species 
are always practically blind and colorless. 
But the animals brought up from the deep 
waters of the ocean are often very brightly 
and conspicuously colored. 
The question at once arises: What is the 
significance of these colors? Are they 
merely fortuitous, or have they a meaning 
that can be deciphered, giving a clue that 
may lead to a further understanding of the 
mysterious realm beneath the waters? It 
SCLENCE. 
847 
is my purpose this evening to attempt to 
answer these questions, but before doing so 
let us examine briefly the main facts re- 
garding the colors of abyssal animals. We 
will call as witnesses some of the naturalists 
of the widest experience in the science of 
thalossography, and supplement this evi- 
dence by facts of personal observation. 
Professor Mosely, of the Challenger staff, 
says: ‘‘ Peculiar coloring matter giving ab- 
sorption spectra has now been found to 
exist in all the seven groups of the animal 
kingdom. The Echinodermata and Ccelen- 
terata appear to be the groups which are 
most prolific in such coloring matter. 
Pentocrinin and antodonin seem to be dif- 
fused in immense quantities throughout 
the tissues of the crinoids in which they 
occur and the Echinoderms generally seem 
to be characterized by the presence of 
evenly diffused and abundant and readily 
soluble pigments.”’ Again, he says: ‘The 
same coloring matters exist in the deep-sea 
animals which are found in shallow water 
forms.” ; 
Alexander Agassiz, than whom no living 
man has had more experience in deep sea 
work, says: “There are many vividly 
colored bathyssal animals belonging to all 
the classes of the animal kingdom and 
possessing nearly all the hues found in liv- 
ing types in littoral waters. * * * There 
is apparently in the abysses of the sea the 
same adaptation to the surroundings as 
upon the littoral zone. We meet with 
highly colored ophiurans within masses of 
sponges themselves brilliantly colored at a 
depth of more than 150 fathoms. * * * 
While we recognize the predominance of 
tints of white, pink, red, scarlet, orange, 
violet, purple, green, yellow and allied 
colors in deep water types, the variety of 
coloring among them is quite as striking 
as that of better known marine animals. 
* %& +k There is as great a diversity in color 
in the reds, oranges, greens, yellows, and 
