74 S IE W. DAWSON ON FOSSIL PLANTS. 



Hemisphei'e. Even in Australia the earl\- Tertiai-y tiora includes many t3'pes now foreign to that 

 country, but resembling those of Upper Cretaceous age in the North, and thus indicating a much 

 greater uniformity in tho-e times than at present, or perhaps that a floia originating in the North 

 had already in the Eocene spread into the Southern Hemispheie. Li generalizing on these subjects, 

 Ettingshausen regards them too much from the point of view of local evolution rather than of migra- 

 tion, and does not sufficient!}^ recognize the great antii^uity of modern tyjics in the Northein 

 Hemisphere, and the certainty that, in the vicissitudes of climate in geological time, thci'e have been 

 many great transportations of iloras fi'om noi'lh to south, and from south to north. The time is 

 rapidly ajjproaching when these gi-eat questions will meet with adequate answers; but the accumula- 

 tion of facts is scarcely as j-ct sufficient. Ettingshauscn's specimens were unfortunately somewhat 

 fi-agmentary, but I have received from Bi-.ron von Mueller a small collection of fossil fruits which 

 show some curious American atfiuities in the Tertiary period. 



