838 
what may be observed to-day in the tropics 
as to the relative abundance of caleareous 
marine plants and caleareous marine ani- 
mals and from what has been determined 
by the study of the cores obtained by boring 
into coral reefs, it would appear that some- 
times the plants predominate and some- 
times the animals. As Dr. Vaughan points 
out, there are good grounds for believing 
that the conditions attending the forma- 
tion of coral reefs in ancient times were \ 
not very different from those that prevail 
at present. In any event, the definition 
quoted above is intended to be a general 
one and its validity is to be tested by 
application to recent and modern condi- 
tions as well as to those of long-past geo- 
logical ages. 
The best-known example of a thorough 
and detailed study of the nature of a 
coral reef is embodied in a quarto work of 
more than four hundred pages published 
by the Royal Society of London in 1904 
and entitled ‘‘The Atoll of Funafuti: 
Borings into a Coral Reef and its Results: 
Being the Report of the Coral Reef Com- 
mittee of the Royal Society.’ Funafuti 
was selected for this study because it was 
considered a ‘‘typical’’ coral reef or island. 
Several borings were made by members of 
the three successive expeditions that visited 
the atoll, the first attempts being only 
partially successful, and the cores thus ob- 
tained were brought back to England for 
careful study. The main boring was finally 
driven down to a depth of 1,1144 feet. 
Inthothamnion, a hard stone-like red coral- 
line seaweed, of the group commonly 
known to zoologists and geologists as 
“‘nullipores,’’ was found to be more or 
less abundant through the entire length 
of the boring; Halimeda, a calcified green 
seaweed, was locally very abundant from 
28 to 1,096 feet in depth. Professor J. W. 
SCIENCE 
[N.S. Vou. XXXV. No. 909 
Judd sums up the general results of the 
analysis of the cores as follows: 
Dr. Hinde’s carefully drawn up lists show that 
from top 2c bottom the same organisms occur, 
sometimes plants, sometimes foraminifera, and 
sometimes corals predominating (p. 174). 
It is to be observed that he mentions 
plants first. Moreover, Mr. A. E. Finckh, 
who was one of the members of the expedi- 
tion and wrote the chapter on ‘‘Biology of 
Reef-forming Organisms at Funafuti 
\ Atoll,”’ definitely groups these organisms 
in order of their reef-building importance 
as follows: ‘‘(1) Inthothamnon; (2) 
Halimeda; (3) the Foraminifera; (4) the 
Corals.’’ It will be noted that the first 
two places in this ranking are given to 
members of the plant kingdom and that the 
corals, the ‘‘most important’’ reef-building 
organisms of Vaughan’s definition and of 
the still prevalent popular belief, are rele- 
gated to a fourth position. This naturally 
raises the somewhat academic, though 
chiefly biologic, question, ‘‘ When is a ‘true 
coral reef’ not a coral reef?’’ It raises 
also a serious question as to whether the 
continued use of ‘‘ coral’’ reef for struc- 
tures that have been built up largely 
through the agency of plants is not 
responsible for false ideas and widespread 
mental confusion. 
That the opinion of Mr. Finckh in regard 
to Funafuti is not his alone, is evident from 
the following statement by J. Stanley Gar- 
diner, who, being a professor of zoology in 
Cambridge University, should be free from 
any suspicion of bias in favor of the 
plants: 
The reef [of Funafuti] seems to have been 
mainly formed by the growth of nullipores, which 
are now building up masses outside the rim and 
adding them on the reef, causing its extension 
seawards.? 
2««The Coral Reefs of Funafuti, Rotuma and 
Fiji, together with some Notes on the Structure 
