84 NATURAL INHERITANCE. [CHAP. 



thicknesses of more than a hundred bodily parts, each 

 so distinct from the rest as to have earned a name by 

 which it can be specified. The list includes about fifty 

 separate bones, situated in the skull, the spine, the 

 pelvis, the two legs, and in the two ankles and feet. 

 The bones in both the lower limbs have to be counted, 

 because the Stature depends upon their average length. 

 The two cartilages interposed between adjacent bones, 

 wherever there is a movable joint, and the single 

 cartilage in other cases, are rather more numerous than 

 the bones themselves. The fleshy parts of the scalp 

 of the head and of the soles of the feet conclude the 

 list Account should also be taken of the shape and 

 set of the many bones which conduce to a more or less 

 arched instep, straight back, or high head. I noticed 

 in the skeleton of O'Brien, the Irish giant, at the College 

 of Surgeons, which is the tallest skeleton in any English 

 museum, that his great stature of about 7 feet 7 inches 

 would have been a trifle increased if the faces of his 

 dorsal vertebrae had been more parallel than they are, 

 and his back consequently straighter. 



This multiplicity of elements, whose variations are to 

 some degree independent of one another, some tending 

 to lengthen the total stature, others to shorten it, 

 corresponds to an equal number of sets of rows of 

 pins in the apparatus Fig. 7, p. 63, by which the cause 

 of variability was illustrated. The larger the number of 

 these variable elements, the more nearly does the varia- 

 bility of their sum assume a "Normal" character, though 

 the approximation increases only as the square root of 



