62 
_Asia do not live solely or principally in southern latitudes, as has been 
shown with respect to the recent larger forms of the so-called Hocene 
formation, but have been observed living both in those and in northern 
latitudes. These recent species also are not rare nor isolated, but fill 
in incalculable numbers the seas of northern Europe, and are not 
wanting on the tropical coasts of the American ocean. 
“The idea that the temperature and constitution of the atmosphere 
and oceans were essentially different at the period of the Chalk forma- 
tion, and adverse to the organized beings at present existing, naturally 
acquired more probability and weight the more decidedly different all 
the creatures of that period were from those of the present time ; but 
loses more and more in importance the less the chalk proves to be a 
chemical precipitate, and the more numerous the forms agreeing with 
those of the present day become by renewed inquiry. Nay, there is 
not the least doubt that the perfectly ascertained identity of a single 
species of the present day with one of those of the chalk, renders 
doubtful the necessary transformation of all the others subsequently 
to the formation of the chalk rocks; how much more so when these 
are numerous, and such as form masses! The size appears to be of 
no importance, as the small organisms have already been shown to 
agree with the large, with regard to the effect of external influences 
upon them. 
‘“« The period of the dawn of the organic creation coexistent with our- 
selves, can only be admitted as being anterior to and below the Chalk 
formation, if mdeed, which is questionable, such a distinction can be 
made ; or the chalk, with its rocks, covering far and high the super- 
ficies of the earth, forms part of the series of recent formations, and, 
since of the four as yet well-established great geological periods of 
the earth’s formation, the quaternary, tertiary and secondary forma- 
tions contain recent organisms, it is as three to one more probable 
that the transition or primary formation is not differently circum- 
