424 Notices of Memoirs — Origin of Tertiary Man. 



vertebrse, part of a sacrum, the middle piece of a humerus, and 

 a calcaneum. There is a characteristic molar tooth of the southern 

 elephant, Elephas atitiqims, while three fragments of tusk and some 

 portions of limb-bones may well belong to the same species. Two 

 bases of shed antlers evidently represent the large extinct fallow 

 deer, Cervus browni, and other bases of antlers are characteristic of 

 Cervus elaphus. Numerous bovine limb-bones are very variable in 

 size and proportions, and may belong either to Bos primigenius or to 

 a Bison. Fragments of limb-bones of a small Rhinoceros are not 

 specifically determinable. The absence of Hippopotamus is curious, 

 but remains of this animal have been found not far away in Cockspur 

 Street and beneath the Admiralty Offices. 



In the London district, as in other parts of Southern England, 

 there is thus some evidence that the typically warm and typically 

 cold members of the Pleistocene mammalian fauna were not altogether 

 contemporaneous. 



II. — A Geological Theory of the Origin of Man. 

 Pkobable Helations of Climatic Change to the Origin of the 

 Tertiary Ape-Man. By Professor Joseph Barrell. The 

 Scientific Monthly (New York), vol. iv, pp. 16-26, 1917. 



LAST year (Bull. Geol. Soc. America, vol. xxvii, pp. 387-436) 

 Professor Barrell pointed out that recurrent periods of semi-arid 

 conditions might have had much influence on the evolution of 

 vertebrate animals. As a dry season advanced, rivers would be 

 reduced in flow, stagnant pools would result, and any fishes which 

 endured these changed conditions would have to become much 

 modified. The primitive sharks, for instance, found in the earliest 

 Palaeozoic f reshwaters, having no air-bladder, would be driven to the 

 seas. The freshwater fishes which remained were ganoids and 

 dipnoans, with an air-bladder efficient for the direct use of air. Prom 

 the crossopterygian ganoids, under the stimulus of the semi-aridity 

 of the Devonian period, there arose the amphibians capable of 

 existing as land animals ; and so on. 



The question now arises as to whether a similar climatic change in 

 the Tertiary period, acting on species of large-brained and progressive 

 anthropoid apes, isolated from forest regions, might not cause them 

 to advance and become adapted for life on plains or die out. 

 Professor Barrell thinks it would be so, and mentions that at the 

 close of the Miocene period climatic conditions were such that this 

 latest evolution may actually have occurred. There were at that 

 time numerous apes in the warm forests south of the Himalayan 

 region. As the mountains rose and the temperature was lowered 

 some of the apes may have been trapped to the north of this area. 

 As comparatively dry plains took the place of forests, and as the apes 

 could no longer migrate southwards, those that survived must have 

 become adapted for living on the ground and acquired carnivorous 

 instead of frugivorous habits. The Miocene or early Pliocene ape- 

 man may therefore be more hopefully sought in deposits of the open 

 and temperate regions of Central Asia than in the alluvial deposits 

 of the more southern tropical forests. 



