deal 
compared with the New World. 263 
mal minutie ; it is the same with the ice of the pole. Still further ; 
the meteoric dusts brought from great distances from the coasts, for 
example 880 marine miles, are also of organic origin. They are 
- composed in great part of microscopic infusoria. There is likewise 
developed, in regions where large organisms cannot exist, a kind of 
life infinitely minute, almost invisible, but incessant. It prevails in 
the eternal night of oceanic depths; while vegetable life, stinrulated 
by the periodical action of the solar rays, is largely diffused over 
continents where the mass of vegetables is incomparably greater 
than that of animals. 
- Nore 13. The strata of the earth not only inclose marine organic 
remains, but also afford numerous traces of terrestrial species. The 
fresh water races, as well as those of salt waters, have in general 
succeeded each other in the direct ratio of the complication of organ- 
ization, the most simple before the most complicated. At the same 
time, the relations between the age of formations and the physiolo- 
gical gradation of the species they inclose, does not appear in a 
regular manner except in the most complicated vegetables, such as 
the gymnosperms, monocotyledons, and dicotyledons. The same 
thing takes place with animals: the vertebrates are striking examples 
of it. Their classes, and to a certain point their families, follow 
each other and have appeared, according to the most general law of 
the ancient.creations. On the other hand, the acrogenous crypto- 
gams, which formed part of the earliest vegetation, have entered 
upon the scene of the world in all their perfection; such has like- 
wise been the case with the cephalopod molluscs. But these vege- 
tables and animals form part of the least complicated class of the 
branches to which they belong. They do not the less prove that 
the perfection of organization which has followed the order of time, 
has operated among the superior divisions, such as classes, rather 
than among orders and families. Nature seems to have arrived at 
the production of the most perfect vegetables and animals only by a 
series of trials, or, if we may so express it, successive attempts. 
Thus the didelphous mammifera, the least complicated of their 
class, have appeared long before the monodelphes, which exhibit 
the maximum of perfection in organism ; the latter have gone through 
many generations, and have seen many of their species perish, be- 
fore becoming the contemporaries of Man, the most perfect being in 
creation. 
Norte 14. Interior reactions have given its form to the surface 
of the globe, by raising chains of mountains through strata much in- 
clined. These reactions have prepared the field where the forces 
of organic life must have begun to operate after the return of tran- 
quillity, in order to develop there the profusion of individual forms. 
These conspicuous upheavals have in a great measure done away, 
in both hemispheres, with that uniformity of level which, had it con- 
tinued, would have rendered the globe uninhabitable. The most in- 
