0^») FORMS OF LIF^ CHANG INQ 



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02T THE FORMS OF LIFE CHAXGIlN^G ALMOST SIMULTA- 

 KEOUSLY THROUGHOUT THE WORLD. 



Scarcely any pal^eontological discovery is more striking 

 than the fact tliat the forms of life change almost simul- 

 taneously throughout the world. Thus our European 

 Chalk formation can be recognized in many distant regions, 

 under the most different climates, where not a frag- 

 ment of the mineral chalk itself can be found; namely, in 

 North America, in equatorial South America, in Tierra 

 del Fuego, at the Cape of Good Hope, and in the peninsula 

 of India. For at these distant points, the organic remains 

 in certain beds present an unmistakable resemblance to 

 those of ihe Chalk. It is not that the same species are 

 met with; for in some cases not one species is identically 

 the same, but they belong to the same families, genera, 

 and sectioiis of genera, and sometimes are similarly char- 

 acterized in such trifling points as mere superficial sculp- 

 ture. Moreover, other forms, which are not found in the 

 Chalk of Europe, but whicli occur in the formations either 

 above or below, occur in the same order at these distant 

 points of the world. In the several successive palaeozoic 

 formatioiis of Russia, Western Europe, and North America, 

 a similar parallelism in the forms of life has been observed 

 by several authors; so it is, according to Lvell, with the 

 Fiuropean and North American tertiary deposits. Even if 

 the few fossil species which are common to the Did and 

 New Worlds were kept wholly out of view, the general 

 parallelism in the successive forms of life, in the palceozoic 

 and tertiary stages, would still be manifest, and the several 

 formations could be easily correlated. 



These observations, however, relate to the marine inhabi- 

 tants of the world: we have not sufficient data to judge 

 whether the productions of the land and of fresh water at 

 distant points change in the same parallel manner. We 

 may doubt whether they have thus changed: if the Mega- 

 therium, Mylodon, Macrauchenia, and Toxodon had been 

 brought to Europe from La Plata, without any information 

 in regard to their geological position, no one would have 

 suspected that they had co-existed with sea-shells all still 

 living; but as these anomalous monsters co-existed with 

 the Mastodon and Horse, it might at least have been in- 



