APRIL 9, 1914] 
NATURE 135 
LETTERS .TO..THE EDITOR. 
[The Editor does not hold himself responsible for 
opinions expressed by his correspondents. Neither 
can he undertake to return, or to correspond with 
the writers of, rejected manuscripts intended for 
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The Funafuti Boring. 
lr was with great pleasure that I read the clear 
statement of Prof. J. W. Judd (Nature, March 12) 
in reply to the letter of Prof. E. B. Poulton (February 
26) upon this subject. Especially welcome was his 
definite statement that all idea of solution of calcium 
carbonate being the causative factor of lagoon forma- 
tion was negatived by the study of the bore. 
But I would direct a caution to those who might be 
inclined to read into Prof. Judd’s letter a vindication 
of the correctness of Darwin’s theory of atoll forma- 
tion. 9 
Suppose it is definitely proved that an atoll such 
as Funafuti is established upon a basis which has 
certainly undergone a movement of sinking. Such a 
finding can only establish the ‘‘validity’’ of a state- 
ment that a sinking basis may become the site of atoll 
development; it cannot establish the ‘‘ validity”? of a 
theory which demands this sinking as the cause of 
the development of the peculiarities of atoll growth; 
especially in the face of the definite knowledge that 
typical atoll growth may be established upon a basis 
which shows either, no evidence of sinking, or actual 
evidence of rising. It is upon this point that I fear 
the recent correspondence may mislead. 
One other question arises: Has it been definitely 
proved that the site of Funafuti atoll has undergone 
a movement of sinking? 
A bore made upon the extreme windward edge of an 
atoll some ten miles in diameter has so inherent a 
probability of penetrating a talus slope, that the most 
rigid proof should be furnished of its having pene- 
trated anything else. This proof is, I think, not forth- 
coming. 
The lagoon bores are not sufficiently deep to estab- 
lish, beyond dispute, the supposition that there has 
been a movement of sinking. The statement of Prof. 
Judd would leave quite an opposite impression, for he 
says that the lagoon bore extended ‘“‘to a depth of 
1oo ft. below the limit of growth of the reef-forming 
corals.” The lagoon bores extended to 36 and 41 
fathoms below the surface of the water. It is obvious 
that to make Prof. Judd’s statement correct he must 
allow the reef-builders only 244 fathoms as their bathy- 
metrical limit. But 244 fathoms is not the ‘lowest 
depth at which, as all naturalists agree, reef-forming 
corals can flourish.’’ 
It is only necessary to mention the dredgings of 
Basset-Smith on the Lizard and Macclesfield Banks 
in which twelve species of typical reef-forming corals 
were obtained from between 31 and 45 fathoms. On 
open oceanic banks, far from any shore’ line from 
which suspended matter may be carried in the water, 
it is possible that even this may not represent the 
bathymetrical limit of the true reef-builders; but it is 
enough that we have positive knowledge of their pre- 
sence at depths exceeding that of the Funafuti lagoon 
bores to negative any idea that these bores can prove 
a downward earth movement. Atoll formations are 
developed in areas in which upward earth movements 
are evident; they are also developed in areas in which 
downward earth movements are evident (though the 
Funafuti bores cannot be accepted as proving it); and 
in neither case can such movement be invoked as the 
cause of their peculiar features. The Funafuti bores 
showed that ‘solution’? was not the cause of lagoon 
NO A23m9, VOL: <93 | 
a 
formation; they did not show that ‘‘ subsidence "’ was 
the cause. It is the study of the coral zooid and the 
coral colony that alone can reveal the picture of atolls 
caused by ‘‘ sedimentation.” F. Woop-Jones. 
WE are quite ready to admit that the evidence 
obtained at Funafuti does not prove that all atolls are 
formed by subsidence. A stationary volcanic bank, 
eroded down to the level at which reef-forming corals 
could begin to flourish, would serve as well for the 
basis of an atoll as a sinking island; this was well 
pointed out by the late Admiral Wharton. So, too, 
would a deeper bank which had been raised to a 
similar level by the raining down upon it of pelagic 
organisms, if it can be shown that such action is 
capable of producing any considerable thicknesses of 
rock. And there are other conceivable ways in which 
atolls may arise, as was fully admitted by Darwin in 
his correspondence with Semper. 
We claim, however, that Funafuti proves that atolls 
can be formed by subsidence from the following facts. 
The upper part of the main boring, as well as several 
subsidiary borings, show the existing reef to consist 
of corals in their position of growth, their interstices 
being filled with broken fragments of coral mingled 
with smaller organisms. Now, right down to the 
extreme depth reached, the cores were of precisely 
similar character; they showed corals in the position 
of growth surrounded by detritus and small organisms. 
Thus the hypothesis of a talus—which, so far as I 
know, was only suggested after the boring was found 
not to reveal.a substratum of foreign rock—falls to 
the ground. 
Although species of corals belonging to genera 
which are reef-forming have been found at consider- 
able depths, the luxuriant growths of coral, necessary 
for building up a great reef, have never been shown 
to take place below 20 to 25 fathoms. This was a 
conclusion that was certainly accepted by the late 
Prof. Alexander Agassiz, from the results of his wide 
experience, as it has been by so many other natural- 
ists. The ingenious method employed in boring in the 
middle of the lagoon of Funafuti did not admit of 
large cores being brought up, but the borings were 
stopped by hard coral-masses, the fragments obtained 
from these indicating that they belong to reef-making 
forms. It is fair, therefore, to maintain that the 
lagoon borings at Funafuti afford valuable evidence in 
support of that obtained by the main boring. 
J... W;s supp; 
Zoological Classification. 
Zoo.LoGIcaL classification of the present day is un- 
satisfactory, and the reason is not far to seek. This 
condition has resulted from the unnecessary multi- 
plication of genera. 
The real object of classification is being lost sight 
of. The objects aimed at in a classification may be 
put briefly as follows :—(1) To give to each animal a 
name, by which it will be known internationally, and 
(2) to give to animals which resemble one another the 
same name. 
The unit-group of animals bearing the same name 
is the genus. How large may the genus be? There 
are at present independent genera which have been 
created out of a formerly existing single genus. Has 
the diagnosis of the species been rendered simpler by 
breaking up the genus, and by giving to each sub- 
genus a new name? Certainly not in several cases. 
The subdivision of the older genus has resulted from 
the more detailed examination of the various species. 
Such investigation cannot be too minutely carried out, 
for it is necessary both from the morphological and 
the diagnostic point of view. But the mistake has 
