540 POPULAR SCIENCE MONTHLY. 



prehension of his methods, jumped at this erroneous conclusion — that 

 he was unaware of the danger of possibly mistaking mere accidental 

 resemblances for morphological affinities, and that he assumed that 

 because two objects, perhaps from widely separated regions, appeared 

 more or less identical in form, and possibly in use, they were neces- 

 sarily to be considered as members of one phylogenetic group. On the 

 contrary, in the grouping of his specimens according to their form and 

 function, he was anxious to assist as far as possible in throwing light 

 upon the question of the monogenesis or polygenesis of certain arts 

 and appliances, and to discover whether they are exotic or indigenous 

 in the regions in which they are now found, and, in fact, to distinguish 

 between mere analogies and true homologies. If we accept the theory 

 of the monogenesis of the human race, as most of us undoubtedly do, 

 we must be prepared to admit that there prevails a condition of unity 

 in the tendencies of the human mind to respond in a similar manner 

 to similar stimuli. Like conditions beget like results; and thus in- 

 stances of independent invention of similar objects are liable to arise. 

 For this very reason, however, the arts and customs belonging to even 

 widely separated peoples may, though apparently unrelated, help to 

 elucidate some of the points in each other's history which remain ob- 

 scure through lack of the evidence required to establish local contin- 

 uity. 



I think, moreover, that it will generally be allowed that cases of 

 1 independent invention ' of similar forms should be considered to have 

 established their claim to be regarded as such only after exhaustive in- 

 quiry has been made into the possibilities of the resemblances being due 

 to actual relationship. There is the alternative method of assuming 

 that, because two like objects are widely separated geographically, and 

 because a line of connection is not immediately obvious, therefore the 

 resemblance existing between them is fortuitous, or merely the natural 

 result of similar forms having been produced to meet similar needs. 

 Premature conclusions in matters of this kind, though temptingly easy 

 to form, are not in the true scientific spirit, and act as a check upon 

 careful research, which, by investigating the case in its various possible 

 aspects, is able either to prove or disprove what otherwise would be 

 merely a hasty assumption. The association of similar forms into the 

 same series has therefore a double significance. On the one hand, the 

 sequence of related forms is brought out, and their geographical distri- 

 bution illustrated, throwing light, not only upon the evolution of types, 

 but also upon the interchange of ideas by transferrence from one people 

 to another, and even upon the migration of races. On the other hand, 

 instances in which two or more peoples have arrived independently at 

 similar results are brought prominently forward, not merely as inter- 

 esting coincidences, but also as evidence pointing to the phylogenetic 



