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Part I. 

 THE DESCENT OR ORIGIN OF MAN. 



CHAPTER I. 



The Evidence of the Descent of Man from some 



Lower Eorm. 



Niture of the evidence bearing on the origin of man — Homologous 

 structures in man and the lower animals — Miscellaneous points ol 

 correspondence — Development — Rudimentary structures, muscles, sense- 

 organs, hair, bones, reproductive organs, &c. — The bearing of these three 

 great classes of facts on the origin of man. 



He who wishes to decide whether man is the modified descendant 

 of some pre-existing form, would probably first enquire whether 

 man varies, however slightly, in bodily structure and in mental 

 faculties; and if so, whether the variations are transmitted to 

 his offspring in accordance with the laws which prevail with the 

 lower animals. Again, are the variations the result, as far as 

 our ignorance permits us to judge, of the same general causes, 

 and are they governed by the same general laws, as in the case 

 of other organisms ; for instance, by correlation, the inherited 

 effects of use and disuse, &c. ? Is man subject to similar mal- 

 conformations, the result of arrested development, of reduplication 

 of parts, &c, and does he display in any of his anomalies rever- 

 sion to some former and ancient type of structure ? It might 

 also naturally be enquired whether man, like so many other 

 animals, has given rise to varieties and sub-races, differing but 

 slightly from each other, or to races differing so much that they 

 must be classed as doubtful species ? How are such races 

 distributed over the world; and how, when crossed, do they 

 react on each other in the first and succeeding generations ? 

 And so with many other points. 



The enquirer would next come to the important point 

 >vhcther man tends to increase at so rapid a rate, as to lead to 

 occasional severe struggles for existence; and consequently t< 



