xiii 
Millepores with foliated and fragile expansions : a 
little farther the coral reddens the depths of the ocean 
with its brilliant branches, soon followed by the Po- 
ly pean madrepores. It is not however before the 
34th degree of northern latitude that these animals 
commence the developement of that grandeur and im- 
mensity that presents itself at every step to the ex- 
tent of a parallel southern latitude ; here they disap- 
pear, after having exhibited the same series of pheno- 
mena observed in the northern hemisphere. 
It is then within the tropics, or in a zone of more 
than sixty degrees expansion, that these beings, these 
animalcula, scarcely visible to the naked eye, and 
whose operations uninterruptedly proceed, eternally 
exercise their empire in a medium whose temperature 
never changes. From the depths of the ocean they 
elevate those immense reefs, that may in their conse- 
quences entertain a communication between the inha- 
bitants of the temperate zones. The naturalist when 
he visits these xnadreporous islands, once covered with 
the ocean, is astonished at their enormity and perfect 
preservation— so perfect, that the sea seems recently 
to have abandoned them ; and frequently the same 
species of Polypidom that crowns the greatest heights, 
and forms the whole island, extends from its shores 
to an endless distance ; so that when the tide retires, 
