274 THE HUMAN SPECIES 



At the Anthropological Congress at Greifsvvald in 1904, 

 Professor Giinther of Miinchen drew attention to the different 

 systems of numeration extant among Asiatic, African and 

 American races. These systems contain certain principles of 

 addition, subtraction and multiplication, which, although they 

 differ widely, yet present numerous features of the closest resem- 

 blance. Hence the question once more arises, whether these 

 systems were acquired spontaneously or borrowed from one 

 another. An instance of the latter process is the Indian zero ; 

 this extended to other races who no doubt learnt to appreciate 

 the immense practical advantage of the cypher in reckoning. 



Weighing is a faculty confined to man. 



FIG. 126. Right reindeer's horn with notches. 



Measuring, however, animals are certainly capable of, at 

 least those animals which work with products of their own 

 tissues, or employ materials of definite length and thickness, or 

 model solid bodies to their own designs. The spider measures 

 the length of the radiating strands of its web, and spaces the 

 transverse strands at regular intervals. The weaver, basket 

 and tailor birds make use only of fibres of given length ; the 

 beaver builds with logs of definite length and thickness ; the 

 woodpecker carves a hole in a tree with the entrance carefully 

 measured ; the kingfisher and sand-martin dig out their nests in 

 the sand according to a constant size and shape, although they 

 bring to the task nothing but their eye and unerring instinct. 

 In the estimation of " mass " animals are able to aid the eye by 



