56 Transactions. — Zoology. 



sureJ by him as 64-7 and 73-5. A well-marked degree of 

 platycnemia is therefore characteristeric of the Maori tibia, 

 contrasting strongly with what the European bone shows in 

 this respect, to which an index of 73-7 is given by Thomson 

 as the result of the measurement of twenty-one specimens. 

 But even among races of a corresponding civilisation the shaft 

 of the Maori tibia is more than usually flattened, as may be 

 seen by referring to the tables of this index as it occurs among 

 other savage races, given in M. Topinard's book and in Mr. 

 Thomson's papers on the subject. 



I have also, following Mr. Thomson, examined all the 

 bones that have come under my observation as to the antero- 

 posterior curvature of the external condyloid surface. I have 

 noted it as convex in twenty-eight cases, as plano-convex from 

 before backwards in ten, as flat in one, and as concave in 

 five. 



Mr. Thomson has also been the first to note the presence 

 of a facet on the anterior margin of the lower end of the tibia. 

 This, though occasionally met with in Europeans, is of much 

 more common occurrence among savages, and is caused by 

 the pressure of the upper surface of the neck of the astragalus. 

 This condition I carefully looked for, and in every bone ex- 

 amined except two a greater or less degree of flattening or 

 hollowing was found to be present. The antero-posterior 

 curve of the shaft is also more pronounced than among Euro- 

 peans ; but, while in some bones the curve ia fairly regularly 

 distributed along the length of the bone, in others it is mainly 

 confined to the upper fourth. 



That the squatting posture is the cause of these last 

 peculiarities admits, I think, of no doubt. They are met with 

 in the living races that adopt that attitude, and are all readily 

 ex]3lained by the contacts, pressures, and muscular strains 

 consequent on that position, which was also universal among 

 the Tvlaoris at the time when the individuals lived whose 

 skeletons I have examined. Till recently, however, platycne- 

 mia has not been put down to the same cause. It is generally 

 said to be due to the muscular development — tibialis posticus — 

 caused by an active life in a rough, hilly country. Professor 

 Havelock Charles,''' however, shov*'S that the tibia of the natives 

 of the Panjab have not only the altered outer condyle, the 

 curved shaft, and the anterior astragaloid facet, but has an 

 average index of platycnemia of 69-9. A mountainous country 

 can have nothing to do with the flattening in this case, while 

 squatting is the universal custom. And I think it not impro- 



* "The Influence of Function as exemplified in the Moi-pliology of 

 the Lower Extremity of the Panjabi " : Journal of Anatomy and Physio- 

 logy, 1893. 



