THE COUNTRY OF THE SHEPHERDS 47 



exerted their influence through obscure psychologic channels al- 

 most impossible to trace. The why of man's distribution over the 

 earth is one of the most complicated problems in natural science, 

 and the solution of it is the chief problem of the modern 

 geographer. 



At first sight the mountain people of the Peruvian Andes seem 

 to be uniform in character and in mode of life. The traveler's 

 first impression is that the same stone-walled, straw-thatched type 

 of hut is to be found everywhere, the same semi-nomadic life, the 

 same degrees of poverty and filth. Yet after a little study the 

 diversity of their lives is seen to be, if not a dominating fact, at 

 least one of surprising importance. Side by side with this di- 

 versity there runs a corresponding diversity of relations to their 

 physical environment. Nowhere else on the earth are greater phys- 

 ical contrasts compressed within such small spaces. If, there- 

 fore, we accept the fundamental theory of geography that there is 

 a general, necessary, varied, and complex relation between man 

 and the earth, that theory ought here to find a really vast num- 

 ber of illustrations. A glance at the accompanying figures dis- 

 closes the wide range of relief in the Peruvian Andes. The cor- 

 responding range in climate and in life therefore furnishes an am- 

 ple field for the application of the laws of human distribution. 



In analyzing the facts of distribution we shall do well to begin 

 with the causes and effects of migration. Primitive man is in no 

 small degree a wanderer. His small resources often require him 

 to explore large tracts. As population increases the food quest 

 becomes more intense, and thus there come about repeated emigra- 

 tions which increase the food supply, extend its variety, and draw 

 the pioneers at last into contact with neighboring groups. The 

 farther back we go in the history of the race the clearer it becomes 

 that migrations lie at the root of much of human development. 

 The raid for plunder, women, food, beasts, is a persistent feature 

 of the life of those primitive men who live on the border of un- 

 like regions. 



The shepherd of the highland and the forest hunter of the 

 plains perforce range over vast tracts, and each brings back to the 



