44 Proceedings of the Royal Irish Academy. 



of the curvature of the lateral condylic surface. Thomson attributes the 

 latter to habitual use of the flexed position of the knee-joint. The articular 

 surface is too damaged in each of the specimens to allow of measurement 

 according to Thomson's method, but I consider that the convexity had been 

 somewhat greater than usual. The association of this condition with the 

 platycnemia described below is interesting, as is also the occurrence of the 

 facet at the lower end of the bone. The three conditions are found together 

 in anthropoids, and are apparently associated with habitual and forcible 

 flexion at the knee- and ankle-joints. 



The remaining part of the upper surface of the tibia calls for no comment 

 save for the strong impressions produced by the cruciate ligaments and the 

 horns of the semilunar cartilages. 



The shafts are chiefly remarkable for the increase in antero-posterior 

 diameter producing flattening, or platycnemia. This is caused by the strong 

 prominence of the upper part of the ridge intervening between the areas for 

 attachment of the tibialis posticus and flexor longus digitorum respectively. 



In one thick bone the lower part of the soleal ridge is enormously 

 developed and very prominent. The area of attachment of the tibialis 

 posticus is increased. If we presume that these people were squatters, we 

 can readily understand the increased development of the tibialis posticus, 

 the flexors, and the soleus, as these muscles would, in the squatting position, 

 serve to balance the leg on the foot, and in rising from that attitude they 

 would be brought into play at the beginning of the act. The platycnemic 

 index was estimated and found to average 69"2, ranging from 607 to 75-8. 

 It is only right to add that the lower indices were obtained from damaged 

 specimens, where absolute accuracy could not be obtained. 



It is interesting to compare these figures with the indices given by 

 Manouvrier and Duckworth : — 



Modern French (males) — Manouvrier, . . 88-2 



(females) „ . . 80-6-108-3 



Negroes „ . . 85 - 3 



Pre-Columbian Venezuelans — Duckworth, . 76 - l 



Maori A, . „ . 777 



) 66 - 6 right side. 



' ( 60-0 left side. 



Old Irish — average of six specimens, . . 69'2 



Maori B, 



In my own series I found the index lower on the right side than on the left. 

 In all the cases the upper part of the origin of the flexor longus digitorum 

 is particularly well defined, and the prominence of the ridge separating it 



