322 TROPICAL NATURE, AND OTHER ESSAYS. 



were abundant in Greece, and several of these appear 

 to have been the ancestors of those now living in Africa ; 

 while two species of giraffes also inhabited Greece and 

 North- West India. Equally suggestive is the occurrence 

 in Europe of such birds as trogons and jungle-fowl 

 characteristic of tropical Asia, along with parrots and 

 plaintain-eaters allied to forms now living in West 

 Africa. 



Let us now inquire what information Geology affords 

 us of changes in land and sea at this period. From the 

 prevalence of early tertiary deposits over the Sahara 

 and over parts of Arabia, Persia, and Northern India, 

 geologists are of opinion that a continuous sea or strait 

 extended from the Bay of Bengal to the Atlantic 

 Ocean, thus cutting off the Peninsula of India with 

 Ceylon, as well as all tropical and South Africa from the 

 great northern continent. 1 At the same time, and down 

 to a comparatively recent period, it is almost certain 

 that Northern Africa was united to Spain and to Italy, 

 while Asia Minor was united to Greece, thus reducing 

 the Mediterranean to the condition of two inland seas. 

 We also know that the north-western Himalayas and 

 some of the high lands of Central Asia were at such a 

 moderate elevation as to enjoy a climate as mild as that 

 which prevailed in Central Europe during the Miocene 

 epoch, 2 and was therefore perhaps equally productive in 

 animal and vegetable life. 



1 Mr. Searles V. Wood, " On the Form and Distribution of the Land-tracts 

 during the Secondary and Tertiary Periods respectively," Philosophical 

 Magazine, 1862. 



2 This part of the Himalayas was elevated during the Eocene period, and 

 remains of a fossil Rhinoceros have been found at 16,000 feet elevation in 

 Thibet. 



