MR WM. TURNER ON VARIABILITY IN HUMAN STRUCTURE. 187 



third toe received a strong tendinous slip from the expanded part of the common 

 flexor tendon, and the two were blended and inserted together (fig. 11). In 

 another, the short flexor tendon for the third toe received an additional slip 

 from the flexor accessorius. 



In the foot, therefore, as in the forearm and hand, intermuscular structures 

 not unfrequently connected together not only the flexor muscles situated on the 

 same plane, but those situated on the superficial and deeper planes. 



The fifty specimens of the flexor muscles of the foot, the special analysis of 

 the mode of arrangement of which I have now recorded, will be sufficient, I think, 

 to show that in the construction of this group of muscles an amount of variation 

 existed much greater than might at first sight have been supposed. In a portion 

 of one muscle alone, viz., the connecting band from the tendon of the flexor 

 hallucis longus, a considerable number of modifications occurred. In the flexor 

 accessorius also great variability was displayed, and in some proportional relation, 

 apparently, to the extent of variation in it and the connecting band, did the 

 flexor communis digitorum undergo certain modifications in its arrangement, so 

 much so, indeed, in certain cases, as to permit those structures to be to a great 

 extent substituted for it in the formation of the deep flexor tendons for some of 

 the toes. 



Variability in the construction of parts, however, was not manifested merely in 

 different individuals, but in the same individual the corresponding structures on 

 opposite sides of the body were by no means symmetrically disposed. Thus, in 

 two of the four examples recorded in the earlier part of the paper in which a 

 supra-condyloid process existed, it occurred only in one arm of each subject in 

 two cases; whils in a third subject, though both humeri exhibited the process, 

 yet the relations of the brachial artery to it on the two sides were by no means 

 symmetrical. The tendons in the left foot, in many of the individuals in whom 

 both feet were examined, varied also more or less from those in the right foot, so 

 that in the construction of the limbs, as well as in the form and arrangement of 

 the organs contained in the great cavities of the body, an asymmetrical disposi- 

 tion of parts is to be looked for. Thus, we arrive at the conclusion that the plan 

 on which the human body is constructed, although constant in all its essential 

 characters, yet admits of variations (within itself as it were) in certain directions 

 and within certr.in limits. Neither form nor structure is absolutely stereotyped, 

 but modifications occur which, when regarded singly, may be considered, perhaps, 

 as slight and of comparatively little importance, yet when viewed collectively, 

 are sufficient to give to the individual well-marked distinctive characters. 



Much has been said and written of late years on the existence of structural 

 differences between the fair and coloured races of mankind, more especially be- 

 tween the white man and the negro,— differences which, according to some 



VOL. XXIV. PART I. 3 E 



