Holtby — Human Bones from an Ancient Burial Ground in Dublin. 41 



marked when the latter was also present. Turner, 1 many years ago, 

 considered that the gluteus maximus had some influence in causing the 

 formation of the lateral flange which is present in platymeria, and particularly 

 refers to it as likely to be caused by pull on this muscle in squatting races. 

 Hepburn 2 states that platymeria is most likely to occur when there is a 

 frequently flexed condition of hip and knee. It appears to be common 

 among squatting races and in ancient bones. Young human femora 

 frequently show some indication of this lateral flange, but the condition 

 usually disappears with age. Whether in youth it is due to the action of the 

 gluteus maximus in balancing the pelvis and raising the body, and to the 

 vasti in climbing movements producing an effect on the young and pliable 

 bone, or to a survival of a condition constant in earlier times, it is difficult to 

 guess. If the lateral flange in young bones is a survival of the nature 

 indicated, we may compare it with the condition of the foetal talus, which 

 frequently shows an extension from the upper articular surface on to the 

 neck, believed to be reminiscent of the. squatting posture presumably adopted 

 by ancestral forms. 3 



In the gorilla, where the gluteus maximus has an extensive attachment 

 to the ischium, this isehio-femoralis mass is inserted into a depression on the 

 back of the shaft, and there is at this point some platymeria indicated by a 

 lateral flange. [Parsons. 4 whose work has been published since this paper 

 was written, believes that the gluteus maximus takes no part in the formation 

 of the lateral flange, and that platymeria is due to the vasti only.] 



The medial flange is not sufficiently marked in any of these old Dublin 

 bones to obscure the lesser trochanter when the bone is viewed from in front. 

 I believe that, when present, it indicates an attachment of the vastus medialis 

 to the medial surface of the shaft, and of the intermedius to the front, the 

 flange itself giving attachment to both muscles. In other words, development 

 of the vastus intermedius has pushed the medialis round to the medial side, 

 and the development of a medial extension of the shaft in this position has 

 allowed of more extensive attachment of both muscles. Where I have seen 

 it in recent Irish bones it has been more pronounced when the shaft was but 

 little curved, though Duckworth 5 seems to think that platymeria is usually 

 well seen in curved and pilastered femora. Bryce 6 records the ease of a negro 

 whom he dissected, where the vastus medialis was confined to the medial 



1 Turner, Challenger Reports and Journal of Anatomy and Physiology, vol. xxi, 1887. 

 - Hepburn, Journal of Anatomy and Physiology, vol. xxxi, 1897. 



3 Keith, "Human Embryology and Morphology." 



4 Parsons, Journal of Anatomy and Physiology, vol. xlviii, 1914. 



5 Duckworth, "Morphology and Embryology." 



6 Bryce, Journal of Anatomy and Physiology, vol. xxxii, 1898. 



a.i.A. pboc, vol. xxxn., sect. b. [(?] 



