358 PHYSIOLOGY CHAP. 



Egyptians, Greeks, and Eomans) and from the Middle Ages 

 prove by what a slow and gradual process of evolution the 

 civilised nations of Europe have attained their present develop- 

 ment a process which may be compared to the slow evolu- 

 tion through which the different animal and vegetable types 

 succeeded one another and were modified or transformed ou 

 the surface of the earth during the long geological periods. 

 Of course this slow progress sometimes suffered checks and 

 reverses, as, for example, the temporary destruction of Greek and 

 Roman civilisation by the barbarians. If we would solve the 

 problem of the origin and development of man we must have 

 recourse to the same source as the zoologist and botanist who 

 would reconstruct the genealogical tree of animal or vegetable 

 types : we must study the remains of individuals of the same 

 type which are preserved in the different geological strata. We 

 are indebted to palaeontology for the most interesting and reliable 

 records of man, as of every other organism. As is well known, 

 these fossil remains are those of different parts of the skeleton, the 

 structure of which allowed of their preservation in the different 

 strata. We do not possess a sufficiently large collection of these 

 fossil human remains to enable us to reconstruct his genealogical 

 tree with absolute accuracy ; the scanty remains, however, which 

 have been brought to light during the last few decades testify to 

 the existence of the human race in a long distant past ; they are 

 tangible evidence of lower forms who once lived and have now 

 become extinct, links between our anthropoid ancestors and man 

 as he is to-day. 



We will consider some of these remains in connection with the 

 question of the origin of the human species. 



The geological period in 'which man, as a form distinct from, 

 other animal forms, first made his appearance is still under 

 discussion, because the discovery of fossilised human remains in 

 petrographical strata whose geological age is certain is of com- 

 paratively rare occurrence. It is, however, certain that recent 

 discoveries have proved the erroueousness of the view hitherto 

 taken by most scientists that man appeared during the quaternary 

 age (diluvial or glacial period). It is now an established fact 

 that man made his appearance in an earlier age, in the last 

 periods (miocene or pliocene) of the tertiary age (Rutot), when 

 Europe had a sub-tropical climate, with the flora and fauna found 

 to-day in hot countries. 



Of the development of man from that remote age down to the 

 periods of historic civilisation (Egyptian, Greek, Roman) we have 

 no direct knowledge based upon historical documents or writings ; 

 it is the subject of pre-history (or esostory}. The only foundation 

 on which it can be reconstructed is the remains of these peoples 

 found in their dwelling-places, and above all in their tombs. Only 



