150 
Agency of Animalcules 
of the organic bodies $ but in specimens from the south of 
Europe the animal remains largely predominate. Ehrenberg 
has made out seventy-one species of these shells, some cal¬ 
careous, some siliceous, including twenty-two species of 
microscopic nautilites, nummulites, and cyprides, and forty 
species of Infusoria ; with these are a few Conferva and 
other minute vegetables. The chalk of the south of Europe is 
without flints, but full of siliceous Infusoria; whilst in the 
chalk of northern Europe there are abundant flinty nodules, 
but no siliceous Infusoria, except in these nodules, as if they 
had been attracted to the nascent nodules from the fluid in 
which they floated. 
Dr. Buckland noticed also the recent discovery by Mr. 
Bowerbank of spicula, and of organic cellular and tubular 
structure, which he refers to parasitic sponges in the black 
substance of chalk flints, which often encloses also alcyonic 
bodies and shells. Admitting, with Professor Ehrenberor 
and Mr. Bowerbank, the large contribution which animal 
remains have supplied to the substance both of chalk and 
flint. Dr. Buckland would refer the earthy portions of the 
chalk, and the inorganic substance of the flint, to segregation 
from the waters in which both the lime and flint were held in 
solution. To a similar segregation from water he would like¬ 
wise assign the origin of the calcareous earthy matrix which 
invests the calcareous exuviae of molluscous and radiated 
animals in the shelly, the encrinal, and coralline limestones of 
the Silurian, Devonian, and carboniferous series, and which is 
still more obviously loaded with organic remains in the forest 
marble and coralline beds of the oolite formation, and also in 
the calcaire glossier, the crag, and fahluns of the tertiary 
series. 
Dr. Buckland next showed the relations of the recent 
Nautilus, Sepia, and Velella to the minute molluscous construc¬ 
tors both of recent and fossil foraminiferous microscopic shells, 
and stated how much the modern discoveries of microscopic 
shells and Infusoria have added to the amount of animal remains 
that are known to have contributed to the formation of lime¬ 
stone. He illustrated the extent to which molluscous animals 
occur in our present seas by Captain Beaver’s discovery, that 
two shoals marked in the charts as sand-banks, between the 
Cape of Good Hope and Mauritius, in lat. 34° 30' S., long. 
27° 30' E., are dense masses of small Medusa, floating in 
w ater more than 150 fathoms deep ; and by Captain Scoresby’s 
calculation of the number of Medusa in a cubic foot of water 
in the Greenland seas, exceeding 100,000. lie also stated that 
the luminous appearance of the sea in summer nights is due 
to the presence of myriads of minute molluscous animals. 
Dr. Buckland next spoke of the microscopic animalcules 
which fill our stagnant ditches and lakes of iresh water: the 
