6 THE DARWINIAN HYPOTHESIS i 



and only at last, after a brief companionship with 

 the highest of the four-footed and four-handed 

 world, rises into the dignity of pure manhood. No 

 competent thinker of the present day dreams of 

 explaining these indubitable facts by the notion 

 of the existence of unknown and undiscoverable 

 adaptations to purpose. And we would remind 

 those who, ignorant of the facts, must be moved 

 by authority, that no one has asserted the incom- 

 petence of the doctrine of final causes, in its 

 application to physiology and anatomy, more 

 strongly than our own eminent anatomist, 

 Professor Owen, who, speaking of such cases, says 

 ("On the Nature of Limbs," pp. 39, 40) " I 

 think it will be obvious that the principle of final 

 adaptations fails to satisfy all the conditions of 

 the problem." 



But, if the doctrine of final causes will not 

 help us to comprehend the anomalies of living 

 structure, the principle of adaptation must surely 

 lead us to understand why certain living beings are 

 found in certain regions of the world and not in 

 others. The Palm, as we know, will not grow in 

 our climate, nor the Oak in Greenland. The 

 white bear cannot live where the tiger thrives, 

 nor vice versa, and the more the natural habits of 

 animal and vegetable species are examined, the 

 more do they seem, on the whole, limited to 

 particular provinces. But when we look into the 

 facts established by the study of the geographical 



