certain Classes in Ethnology/, 327 



more generally admitted by the best and most competent in- 

 quirers. Forms as extreme as any that can be found within 

 the pale of the same species are to be found within that of the 

 species Homo. Transitions as gradual as those between any 

 varieties elsewhere are also to be found. In summing up the 

 value of the data supplied by man towards the natural history of 

 varieties, it may be said that they are those of a species which has 

 its geographical distribution everywhere, and a moral as well as 

 a physical series of characteristics. Surely if the question under 

 notice be a question that must be studied inductively, Man gives 

 us the field for our induction. 



Before I come to the special point of the present notice, and 

 to the explanation of its somewhat enigmatical heading, I must 

 further define the sort of doctrine embodied in what I have called 

 the belief of the unity of our species. I do not call the upholder 

 of the developmental doctrine a believer of this kind. His views 

 — whether right or wrong — are at variance with the current 

 ideas attached to the word species. Neither do I identify with the 

 recognition of single species the hypothesis of a multiplicity of 

 protoplasts, so long as they are distributed over several geogra- 

 phical centres. The essential element to the idea of a single 

 species is a single geographical centre. For this, the simplest 

 form of the protoplast community is a single pair. 



All this is mere definition and illustration. The doctrine 

 itself may be either right or wrong. I pass no opinion upon 

 it. I assume it for the present ; since I wish to criticize certain 

 terms and doctrines which have grown up under the belief in it, 

 and to show, that, from one point of view, they are faulty, from 

 another legitimate. 



It will simplify the question if we lay out of our account alto- 

 gether the islands of the earth^s surface, limiting ourselves to 

 the populations of the continent. Here the area is continuous, 

 and we cannot but suppose the stream of population by which 

 its several portions were occupied to have been continuous also. 

 In this case a population spreads from a centre like circles on a 

 still piece of water. Now, if so, all changes must have been 

 gradual, and all extreme forms must have passed into each other 

 by 7neans of a series of transitional ones. 



It is clear that such forms, when submitted to arrangement 

 and classification, will not come out in any definite and well- 

 marked groups, like the groups that constitute what is currently 

 called species. On the contrary, they will run into each other, 

 with equivocal points of contact, and indistinct lines of demar- 

 cation ; so that discrimination will be difficult, if not impracti- 

 cable. If practicable, however, it will be effected by having recourse 

 to certain typical forms, around which such as approximate most 



