4 On the Foraminifera of America, and 
We must ascribe the obscurity in which the Foraminifera 
have remained to the difficulty of their observation and to 
the comparatively trifling results generally obtained from the 
investigation of microscopic bodies ; and yet there are few 
branches of study more accessible to every one, and which 
afford more important consequences. Should an observer be 
resident on any coast whatever of the various quarters of the 
globe, or on any tertiary, chalk, or oolite formation of a con- 
tinent, he will find everywhere under his feet an immense 
multitude of Foraminifera, for whose examination a simple 
lens is sufficient. In regard to the importance of the study, 
it ought to possess equal interest for geologists as for zoolo- 
gists ; for the first, because it enables them to determine the 
temperature of the regions in which the fossil animals lived, by 
means of a comparison with those which still live in our seas, 
and also, because it gives them information respecting the for- 
mation of certain strata, questions of the highest importance 
for the history of our planet; and, for the last, from the ele- 
gance of the forms of these animals, from their peculiarity of 
organization, and finally, because they constitute one of the 
most numerous classes of animals, and, notwithstanding their 
minuteness, play an important part in nature. 
The facts relating to the geographical distribution of the 
Foraminifera are extremely interesting. Theauthorhas brought 
together eighty-one species from the coasts of the two sides of 
South America, a number which already affords data for cer- 
tain conclusions, but which will doubtless be afterwards in- 
creased. 
The configuration of the coasts, their greater or less depth 
of water, their particular nature, and more especially the 
direction of the great currents, have the greatest influence 
on the distribution and the number of species of marine ani- 
mals. The configuration of South America is well known ; 
every one is aware that the narrow point stretching towards 
the pole forms the most distinctly marked boundary between 
the Atlantic and the Pacific Oceans; but no one knows that 
there the direction of the currents contributes not less than 
the configuration of the land to disunite the two oceans. The 
great currents from the south-west polar regions which flow 
