AND HIS COTEMPORAKIES. 585 



was put forward that the Pliocene and Post-Pliocene forma- 

 tions in England yielded three distinct species of Elephant 

 besides the Mammoth, namely Elephas meridionalis of Nesti, 

 E. antiquus, and E. priscus. It was inferred also that cor- 

 responding* results would follow a close study of the other 

 Ungulate genera, such as Rhinoceros, but a compulsory de- 

 parture to India on service, in 1847, prevented me from pur- 

 suing the investigation at the time. On my return to 

 Europe, in 1855, fresh from the study of the fossil remains 

 of the 'Ancient Alluvium' of the Jumna, and of their possible 

 bearings on the antiquity of man (antea, p. 580), I deter- 

 mined to take up the examination of the extinct Mammalia 

 of the Pliocene and Quaternary periods in Europe as a 

 monographic labour ; in short, to apply to the deposits, 

 palBeontologically, the same kind of analysis which Mr. 

 Prestwich was applying to them stratigraphically, but with- 

 out concert with or even personal knowledge of him at the 

 time. The object held in view was, first to endeavour to deter- 

 mine with precision the specific characters of the Mammalian 

 forms which occur in the Pliocene strata of the Sub- Apennines, 

 and in equivalent formations elsewhere ; next, to ascertain 

 their range of existence in time, and then to deal in the same 

 manner with the forms which make their appearance in the 

 Quaternary deposits. In this way, it was expected that it 

 would be seen when the older forms ceased, and when the 

 newer forms came in ; or whether the latter passed gradually 

 into the former. The Mollusca appeared to fail here in an 

 important respect as guides, the percentage of extinct spe- 

 cies in the newer Quaternaries being either nil or excessively 

 small, while the Mammalia promised to furnish a test of 

 greater significance : 1st, because the genera and species 

 are everywhere shown to be of more limited duration in time 

 than the Mollusca ; 2nd, because from the vastly greater 

 complexity of their relative functions, they are much more 

 susceptible of being affected by the altered climatic con- 

 ditions which are necessarily involved in every great phy- 

 sical change, and which conduce most to the extinction of 

 species. 



Another object was held in view, upon which it was anti- 

 cipated that the investigation might throw important light — 

 namely, the permanence or mutability of species. Between 

 the Pliocenes of the Sub-Apennines and the newer Quaternary 

 formations an enormous lapse of time had intervened — 

 amounting to many hundreds of thousands, if not millions, of 

 years — during which a great portion of the Continents of 

 Europe, Asia, and America had been chilled down to an ex- 

 tent to which the past history of our planet furnished no 



