Land Connections of the African Continent 33 



chiei argument in their favour is the occurrence of lemurs in 

 Madagascar. As shown by Gregory these lemurs have radiated 

 out from a single type, the European Eocene Adapidae, and it 

 is very probable, that the ancestor of the Madagascar lemurs 

 drifted over from the African mainland on a natural raft 

 There are a fev^ small carnivores, some insectivores and some 

 rodents and each of these groups has, according to Matthew, 

 apparently evolved on the island from a single type introduced 

 long ago by means of a raft. There is further a shrew, a bat, 

 a hippo and a bush-pig. The shrew and the bush-pig have 

 probably been introduced by man (the latter in accord with 

 certain customs of the Malays), the hippopotami may have ar- 

 rived by swimming, while the bats may have arrived by flight. 

 The extinct ground birds of the southern continents and islands 

 have developed from quite different flying birds. In '* Die 

 Banier " of May, 1 92 1 , Dr. Dreyer of Bloemfontein advocates 

 a boggy land bridge between Madagascar and Africa in re- 

 latively recent times, and explains the absence of bog-living ante- 

 lopes from the island by assuming, that they had not arrived in 

 Africa during the existence of this bridge. We must then assume 

 either the same for the elephant, rhinoceros, warthog, monkeys in 

 fact for a large part of the African fauna, or that the land bridge 

 was too boggy for them. This last, however, is difficult to con- 

 ceive, especially from the physical point of view. 



The distribution of the Glossopteris flora and the Permian 

 reptiles can find a much better explanation than by a Gondwana- 

 land and South Atlantic. At the beginning of the Permian 

 Period, South and Central Africa, India, Australia and South 

 America were covered by ice. It is quite clear that under these 

 circumstances no fauna or flora could exist. The fauna and flora 

 which left remains in postglacial sediments must, therefore, have 

 ccme from elsewhere. As the southern icefield advanced north- 

 wards the climate of the northern hemisphere became gradually 

 severer. The Upper Carboniferous flora and fauna which still 

 flourished in western Europe, suffered more and more under the 

 change of conditions. Those species which, for some reason or 

 other could not adapt themselves to the new conditions or could 

 not migrate, became extinct. The flora and fauna which already 



