LAMARCK’S WORK IN GEOLOGY 115 
geology were feebly grasped, and scientific reasoning 
or induction was in its infancy. 
“T would again inquire how, in the supposition of 
a universal catastrophe, there could have been pre- 
served an infinity of delicate shells which the least 
shock would break, but of which we now find a great 
number uninjured among other fossils. How also 
could it happen that bivalve shells, with which cal- 
careous rocks and even those changed into a silicious 
condition are interlarded, should be all still provided 
with their two valves, as I have stated, if the animals 
of these shells had not lived in these places ? 
“There is no doubt but that the remains of so 
many molluscs, that so many shells deposited and 
consequently changed into fossils, and most of which 
were totally destroyed before their substance became 
silicified, furnished a great part of the calcareous 
matter which we observe on the surface and in the 
upper beds of the earth. 
“Nevertheless there is in the sea, for the formation 
of calcareous matter, a cause which is greater than 
shelled molluscs, which is consequently still more 
powerful, and to which must be referred ninety-nine 
hundredths, and indeed more, of the calcareous matter 
occurring in nature. This cause, so important to 
consider, is the existence of coral/igenous polyps, which 
we might therefore call zestaceous polyps, because, like 
the testaceous molluscs, these polyps have the faculty 
of forming, by a transudation or a continual secretion 
of their bodies, the stony and calcareous polypidom 
on which they live. 
“In truth these polyps are animals so small that 
a single one only forms a minut2 quantity of calca- 
reous matter. But in this case what nature does not 
obtain in any volume or in quanti'y from any one 
individual, she simply receives by the number of ani- 
mals in question, through the enormous multiplicity 
