MERISTIC VARIATION 



69 



to decide in the living subject whether or not there was a 

 doubling of the bones of the forearm. The eight fingers were in 

 two groups of four each, with a wide space between. The two 

 " hands " were thus opposed to each other and could be folded 

 upon each other. The power of independent action of these 

 digits was limited, showing an insufficient supply of muscles. If 

 the two index fingers, iv and v (really n and n), were extended, 

 the other six could be flexed ; either group of four could be 

 flexed independently of the other, or the three fingers of either 



FIG. 19. Symmetry within the variable part. Here it would seem that an attempt 

 has been made to repeat the hand, or rather that an attempt at repetition of 

 the thumb has resulted in a doubling of the hand. After Bateson 



hand could be flexed alone. The index fingers alone could not 

 be flexed while the other six were extended. 



Bateson gives several other cases of " double hand" (Nos. 

 496-500), all giving the impression that the doubling is not 

 simply of digits but of a hand as a whole. His No. 5 1 3 is the 

 case of a double thumb, in which the two are symmetrically 

 opposed to each other. 



It is unfortunate for our purpose that so large a proportion of 

 cases cited as examples of meristic variation should be among 

 human subjects. This is only because it is here that the matter 

 has been most studied. The idea has been advanced that domes- 

 ticated species are more variable than wild ones, and man more 

 variable than his simian congeners. The point is not well taken, 

 because careful study shows the ape, the chimpanzee, the baboon, 

 and the gorilla to present the same meristic deviations in respect 

 to digits and the same abnormalities in dentition as are found 



