304 THE ORIGIN OF SPECIES 



be found ; namely in North America, in equatorial South America, 

 in Tierra del Fuego, at the Cape of Good Hope, and in the penin- 

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

 certain beds present an unmistakable resemblance to those of the 

 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 sections of genera, and sometimes 

 are similarly characterized in such trifling points as mere super- 

 ficial sculpture. Moreover, other forms, which are not found in 

 the Chalk of Europe, but which 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 formations 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 Lyell, with the European and North American 

 tertiary deposits. Even if the few fossil species which are com- 

 mon to the Old and New Worlds were kept wholly out of view, 

 the general parallelism in the successive forms of life, in the 

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

 several formations could be easily correlated. 



These observations, however, relate to the marine inhabitants 

 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 Megatherium, 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 a.s these anomalous monsters co-existed with the Masto- 

 don and Horse, it might at least have been inferred that they had 

 lived during one of the later tertiary stages. 



When the marine forms of life are spoken of as having changed 

 simultaneously throughout the world, it must not be supposed 

 that this expression relates to the same year, or to the same cen- 

 tury, or even that it has a very strict geological sense; for if all 

 the marine animals now living in Europe, and all those that lived 

 in Europe during the pleistocene period (a very remote period as 

 measured by years, including the whole glacial epoch) were com- 

 pared with those now existing in South America or in Australia, 

 the most skilful naturalist would hardly be able to say whether 

 the present or the pleistocene inhabitants of Europe resembled 

 most closely those of the southern hemisphere. So, again, several 

 highly competent observers maintain that the existing produc- 



