414 ORIGIN OF LIFE IN AMERICA 



It took place, in fact, in very remote times, probably during 

 the dawn of the Tertiary Era ; and only such forms as were 

 capable of preserving their specific and generic characters 

 till the present day clearly reveal their northern origin. 



The flora of the New World, as I remarked in the paper 

 just referred to, retains even more pronounced traces of that 

 curious relationship between the south-western areas of its 

 two continents.* As among the fossil mammals so do we 

 find also among the fossil plants, a remarkable affinity in late 

 Mesozoic deposits between species from Argentina and from 

 western North America. Professor Berry tells us that in 

 mid-Cretaceous times seventy-five per cent, of the known 

 plants of Argentina were characteristic types of the Dakota- 

 group flora of North America. During a period of geological 

 history when a large section of the existing western part of 

 South America was under water, there was this extraordinary 

 similarity between two regions lying at such a great distance 

 from one another. Professor Berry justly argues that the 

 surprising affinity of these floras to one another points to a 

 community of origin. In these ancient plant deposits of 

 Argentina all the familiar northern genera such as Lirio 

 dendron, Liquidambar, Cinnamomum and Sassafras are met 

 with. Even Platanus, Populus, Quercus and other modern 

 genera are represented. No wonder that Professor Berry f 

 came to the conclusion that a geographical connection must 

 have existed between North and South America during mid- 

 Cretaceous times. During Cretaceous and early Tertiary 

 times the genus Sequoia, to which the Californian red-wood 

 and big-trees belong, likewise ranged from North America to 

 Chile. And it is now held by many botanists that the fossil 

 Sequoia langsdorfi is identical with the still living big-tree 

 (Sequoia gigantea) of California. We possess no fossil testi- 

 mony of the occurrence of the smaller deciduous plants in 

 those remote times, but to judge from the fact that many of 

 the Mesozoic genera of trees still survive to the present day, 

 certain persistent deciduous species presumably did so too. 

 Mr. Engelhardt $ records a number of plant remains from the 



* Scharff, E. F., " Early Tertiary Land-connection," pp. 523 526. 

 f Berry, E. W., " Mid-Cretaceous Geography," p. 510. 

 I Engelhardt, H., " Tertiarpflanzen von Chile," p. 635, 



