116 PROF. J. LOGAN LOBLEY, F.G.S., F.R.G.S.^, ON THE HISTORY 



animals and the expulsion of the aborigines. The subject has beei? 

 ably developed by Dr. Alfred Wallace and Dr. Sclater, but newer 

 light has been thrown upon it by observations on the relations of 

 land and sea which brought about (as I believe) the Glacial Epoch. 



The Pliocene period, as Professor Lobley has stated, was remark- 

 able for great earth moA^ements, causing elevation of the land and 

 sea bed over the Europasian area, and consequent lowering of the 

 climatic temperature. At the beginning of that period, Africa was 

 isolated from Europe and Western Asia by a broad sheet of sea- 

 water — but as time went on land arose at intervals all along the 

 Mediterranean from the Atlantic westward — and three causeuwjs- 

 were formed as lines of communications between Southern Europe- 

 and Western Asia, converting the Mediterranean into a succession 

 of lakes — unquestionably fresh-water lakes. 



Now we have heard how Europe and Asia were inhabited by 

 animals largely representative of those of the present day — namely^ 

 huge pachyderms, ruminants, and ferocious felines, such as the 

 lions, leopards and hysonas, which had migrated from the Asiatic- 

 region, but their range was bounded by the Atlantic and Mediter- 

 ranean waters. We have now to enquire, what were the races of 

 animals inhabiting the adjoining continent of Africa at the same 

 period 1 We have learned from the researches of the authors referred 

 to that the predominant forms were those of the semi-apes, known as 

 the Lemurs, which have given the name to a region including 

 Madagascar ; but the pachyderms, the felidse, the ruminants and 

 other forms then flourishing in the Europasian continent were absent 

 from " the dark continent." However, the period and opportunity 

 for a migration southwards into Africa gradually approached and 

 was ultimately reached. Towards the close of the Pliocene period 

 the three great causeways uniting the two continents above referred^ 

 to arose from the ocean — one at Gibraltar Straits, the second 

 between Sicily and Africa at Algiers, including Malta, and the third 

 across the Isthmus of Suez. Impelled by the increasing cold of the 

 approaching Post-pliocene or Glacial Epoch, those animals unable to 

 endure the rigors of an Arctic climate instinctively bent their steps- 

 southwards ; they crossed the causeways and entered the warm 

 plains of Africa, driving before them the Lemurs and other humbler 

 forms of animals, until they were exterminated or only found refuge 

 in the Island of Madagascar — now separated by a deep gulf — but one 



