- Fan. 20, 1870] 
ee. _ NATURE 
oss) 
day’s Nature (January 13). The researches of Helmholtz 
and others have (as is well known) overthrown, to a certain 
extent, the old idea of the three primary colours—red, blue, 
and yellow—and have shown that if any ¢/7e are to be selected, 
red, blue, and green have greater claims than the former. Now, 
in Mr. Barrett’s diagram these correspond to the following 
notes :— 
Red. Yellow. Green. Blue-Indigo. 
(93 E. F. G. 
Tonic. Third. Sub-dominant. Dominant. 
The old triad, red, yellow, blue, correspond to the common 
chord ; but the new triad, red, green, and blue, to the ¢ozc, sudb- 
dominant (or fourth) and dominant (or fifth) ; or, in other words, 
to the three notes which constitute in music the frazdamental base 
of the scale. F. De CHaumont, M.D. 
Army Medical School, Netley, Jan. 14 
Government Aid to Science 
I CANNOT but feel flattered that my letter on this subject should 
have been thought so dangerous as to require a leading article in 
the same number by way of immediate antidote, but I must beg 
you to allow me to correct one or two errors into which you have 
fallen as to the views I really hold, and which it seems I failed 
clearly to express. You say, you ‘‘ understand Mr. Wallace to 
mean that the main result of cultivating science is merely the 
gratification of those directly engaged in the pursuit, and that 
they who do not take this personal interest in it derive little or 
no benefit from it.” 
The first half of this passage does express, though imperfectly, 
what I believe to be the truth ; the latter half expresses the exact 
opposite of what I have ever thought or intended to write on the 
subject.. The main result of the cultivation of science I hold to 
be, undoubtedly, the elevation of those who cultivate it to a 
higher mental and moral standpoint ; while the secondary, but 
not less certain result, is the acquisition of countless physical, 
social, and intellectual benefits for the whole human race. But 
if these are the secondary and not the Jrimary results of cultivat- 
ing science, it seems to me to be radically unsound in principle, 
and sure to fail in practice, if by means of any system of State 
support we seek to find a short cut to these secondary results. 
The only logical foundation for advocating the furtherance of 
scientific discovery by the expenditure of public money, would 
be the belief that science can be most successfully pursued by 
those whose chief object is to make practical and valuable dis- 
coveries ; whereas the whole history of the progress of science 
seems to me to show that the exact opposite is the case, and that 
it is only those who in a noble spirit of self-sacrifice give up their 
time, their means, even their lives, in the eager and loving search 
after the hidden secrets of Nature, who are rewarded by those 
great discoveries from which spring a rich harvest of useful 
-applications. 
One more point: I do not admit that it is just to tax the com- 
munity for all the Government institutions you name, but in the 
short space at my command I could not go into details. I have 
stated how I think some of these institutions require modifica- 
tion to make them accord with the fundamental principle of just 
government ; and if that principle is a sound one, it is easy to see 
in what way the others should be dealt with. As an example I 
may indicate, that a detailed survey, like that of the large-scale 
Ordnance-maps, being primarily a boon to the landowners of the 
country, should not be w/o//y paid for by the public. 
ALFRED R, WALLACE 
Food of Oceanic Animals 
I FIND on my return home that Dr. Wallich is vexed at my 
not having given him the credit of having already answered the 
question which I ventured to put in the ninth number of NATURE, 
and that he apparently accuses me of inconsistency as regards 
my estimate of his observations on deep-sea life. I hasten to 
assure him that my opinion in that respect has never changed ; 
nor do the extracts which he has given from my reports warrant 
such an inference. 
I certainly overlooked some of his remarks in the ‘* North 
Atlantic Sea-bed”” bearing on my question, in which he says 
(page 131), it may be asked ‘‘ under what other conditions than 
exceptional ones can marine animal life be maintained without 
the previous manifestation of vegetable life, as must be the case 
if it exists at extreme depths?” And he answers this inquiry 
by submitting that “in the majority of the marine Protozoa—as 
- for instance in the Foraminifera, Polycystina, Acanthometre, 
j 
| 
Thalassicollidze, and Spongidee—the proof of these organisms 
being endowed with a power to convert inorganic elements for 
their own nutrition, rests on the indisputable pcwer which they 
possess of separating carbonate of lime or silica from waters 
holding these substances in solution.” But this does not appear 
to be a satisfactory answer to the inquiry; because a limpet 
separates carbonate of lime from sea-water in order to 
construct its shell, yet it cannot be assumed that this 
animal (which is well known to be a vegetable-eater) has 
also the power of converting other inorganic substances for 
its own nutrition. Among the Protozoa, many, probably all; 
of the Rhizopods are auimal-eaters. With regard to sponges, 
Dr. Bowerbank says (Mon. I., p. 122) that in the greater 
number their nutriment ‘‘is probably molecules of both animal 
and vegetable bodies, either living or derived from decomposi- 
tion,” and that ‘‘ the fecal matters exhibit all the claracteristics 
of haying undergone a complete digestion.” 
J. GWYN JEFFREYS 
P.S.—In the 1oth number of Nature, Dr. Martin. Duncan, 
under the head of ‘* Deep-Sea Corals,” opposes a statement in 
what he calls a postscript to my report on the ‘“ Deep-Sea 
Dredging Expedition in H.M.S. Porcupine.” | This statement 
was not part of my report, nor had I anything to do with it. 
ied 
My attention has been directed to a paragraph in one of the 
late numbers of NATURE referring to Professor Dickie’s interest- 
ing remarks on the bathymetrical distribution of Alga, and raising 
the question of the mode of nutrition of the great sheet of animal 
life, which is now shown to extend over the bottom of the sea 
at all depths. 
This curious problem was of course one of the first which 
engaged our interest when working up the results of the dredging 
cruise of the Lightning. In April last, I proposed a-solution 
in one of the ‘*Afternoon Scientific Lectures” in connection 
with the Royal Dublin Society, which was afterwards reprinted 
in full in the *‘ Annals and Magazine of Natural History.”~ I 
see from notices in several newspapers that this question has 
excited considerable interest; I may, perhaps, therefore be 
allowed to quote the passage in the lecture specially bearing 
upon if :— 
“The question of the mode of nutrition of animals at these 
great depths is a very singular one. The practical distinction 
between plants and animals is, that plants prepare the food of 
animals by decomposing certain inorganic substances which 
animals cannot use as food, and recombining their elements into 
organic compounds upon which animals can feed. This process 
is, however, constantly effected under the influence of light. 
There is little or no light in the depths, and naturally there are 
no plants: but the bottom of the sea is a mass of animal life. _ 
On what do these animals feed? The answer seems to be suffi- 
ciently simple: nearly all the animals—practically a// the animals, 
for the small number of higher forms feed upon these—belong to 
one sub-kingdom, the Protozoa, whose distinctive character is that 
they have no special organs of nutrition, but that they absorb nou- 
rishment through the whole surface of their jelly-like bodies. Most 
of these animals secrete exquisitely-formed skeletons, sometimes 
of lime, sometimes of silica. ‘Uhere is no doubt that they extract 
both of these substances from the sea-water, although silica often 
exists there in quantities se small as to elude detection by 
chemical tests. All sea-water contains a certain proportion of 
organic matter in solution. Its sources are obyious. All rivers 
contain a large quantity : every shore is surrounded by a fringe 
which averages about a mile in width of olive and red sea-weeds : 
in the middle of the Atlantic there is a marine meadow, the 
Sargasso Sea, extending over three millions of square miles : the 
sea is full of animals which are constantly dying and decaying ; 
and the water of the Gulf Stream, especially, courses round 
coasts where the supply of organic matter is enormous. It is, 
therefore, quite intelligible that a world of animals should live in 
these dark abysses, but it is a necessary condition that they 
should chiefly belong to a class capable of being supported by 
absorption, through the surface, of matter in solution ; developing 
but little heat, and incurring a very small amount of waste by 
any manifestation of vital activity. According to this view, it 
seems highly probable that at all periods of the earth’s history, 
some form of the Protozoa, rhizopods, sponges, or both, pre- 
dominated greatly over all other forms of animal life in_ the 
depths of the warmer regions of the sea ; whether spreading, 
compact, and reef-like, as the Laurentian anc Paleozoic eozoon ; 
