Mr. Couthouy’s Reply to Mr. Dana. 385 
to a certain extent, the corals are limited in their range of growth 
by temperature rather than depth, and that wherever this is not 
below 76° Fahrenheit, there, ceteris paribus, they will be found to 
fiourish as in the Polynesian seas ;’* and again, ‘among the 
Paumotus, the field of their most lavish display, the temperature 
varies from 77° to 83°. At Tahiti, from 77° to 80°, and about 
the same at the large groups to the west of it. At the Hawaiian 
Islands, laying between 19° and 22° north latitude, it is some- 
times as high as 81°. In our own hemisphere, among the An- 
tilles, Bahamas, and southern coasts of Florida, I have found the 
temperature of the water near the shore, at different seasons, 
from 78° to 82°, and in all these regions coral reefs abound.” + 
I have italicised in the preceding quotations, the passages proving 
most clearly the falsity of Mr. Dana’s representation of my opin- 
ions in regard to a limiting temperature, and I appeal with con- 
fidence to every candid and honorable mind, whether they do 
not completely disprove his assertion, that I named 76° Fahren- 
heit as the temperature limiting the growth of corals? whether, 
on the contrary, I have not specially designated it as the temper- 
ature suited for their utmost development ? 
Certainly, no unprejudiced person will attempt to deny, that 
there is a wide difference between affirming, that wherever the 
temperature is not below 76° Fahrenheit, there corals will be 
found to flourish in perfection—that where that exists, is ‘the 
field of their most lavish display,” and stating that when it is be- 
low that, they will not grow at all. ‘To deny this, would involve 
the utter absurdity of assuming that there were no intermediate 
grades of temperature, between the one suited to their most lavish 
growth, and that in which they become extinct. In this matter 
I claim only to be allowed to mean what I have said, in regard to 
temperature as limiting the growth of corals, and protest against 
its being assumed that I mean any thing more. I ask that the 
language of my article on coral formations be taken in its strict 
literal import, and I challenge Mr. Dana to point to a single pas- 
* Boston Jour. Nat. Hist. Vol. IV, p. 76. 
t Ibid. p. 160. Although it is perhaps unnecessary, I will here remark, that the 
temperatures here given are unless the contrary is expressly mentioned, those of 
the surface, as shown by a common thermometer placed in a bucket of freshly 
drawn water, or held in the sea by hand, while sailing or pulling along the reefs 
in a boat. 
Vol. xiv, No. 2.—July-Sept, 1843. 49 
