66 Royal Institution .*— 



Palestine would then be East African. Afterwards the glacial 

 inroad would destroy the mass of preexisting life, excepting the few 

 species most tenacious of existence, which survive in the still com- 

 paratively warm depression of the Jordan valley, which thus became 

 a tropical "outlier," analogous to the boreal marine outliers of our 

 own seas. The Indian types are explained by the former continuous 

 miocene continent from India to Africa. The peculiar species may 

 either yet be found in Arabia, or, if not, may be descendants of 

 species which inhabited the country with a limited range, or may be 

 variations stereotyped by isolation. 



The peculiar fishes of the Jordan are most important, dating 

 yjrobably from the earliest period after the elevation of the land. 

 The genera of the peculiar species are exclusively African, while the 

 species are representative rather than identical. We may explain 

 this by the miocene chain of freshwater lakes, extending from Galilee 

 to the Nyanza, Nyassa, and Zambesi, when an ichthyological fauna 

 was developed suited to the warm conditions that prevailed, part of 

 which survives in the Jordan. 



During the glacial period Lebanon must have been similar in 

 temperature to the present Alps, as the existing mammals and birds 

 on the summits are identical with those of the Pyrenees and the 

 Alps *; not !3o the glacial flora, of which almost every trace has been 

 lost. But the flora had not the same powers of vertical migration 

 with the fauna, of which, however, the Elk, Red Deer, and Reindeer, 

 found in the bone-caverns, have long since perished. 



During the present period the Mediterranean forms have over- 

 spread the whole country, excepting the mountain-tops at an eleva- 

 tion of 9000 feet and the Jordan depression. These two exceptions 

 can be best explained by the fact that the traces of the glacial inroad 

 are not yet wholly obliterated, and that the preceding warm period 

 has left its yet stronger mark in the unique tropical "outlier" of the 

 Dead- Sea basin, analogous to the boreal outliers of our mountain- 

 tops, the concave depression in the one being the complement of the 

 convex elevation in the other. 



ROYAL INSTITUTION OF GREAT BRITAIN. 

 February 7, 1868. 



" On the Animals which are most nearly intermediate between 

 Birds and Reptiles." By Professor Huxley, LL.D., P.R.S. 



Those who hold the doctrine of Evolution (and I am one of them) 

 conceive that there are grounds for believing that the world, wdth all 

 that is in it and on it, did not come into existence in the condition in 

 which we now see it, nor in anything approaching that condition. 



On the contrary, they hold that the present conformation and com- 

 jDOsition of the earth's crust, the distribution of land and water, and 

 the infinitely diversified forms of animals and plants which consti- 

 tute its present population, are merely the final terms in an immense 

 series of changes which have been brought about, in the course of 



