463 



from which follows, 



X= 17-62 oz. 

 F= 8-15 oz. 



and 



VX^TY' = 19-41 oz. 

 •^= 0-4625 = tan (24° 49'). 



The resultant direction of the moment of the glntseal muscles is repre- 

 sented by the line ^x, which nearly coincides with the ilio-pectinseal 

 ridge, and lies somewhat inside a tangent plane from the centre of the 

 acetabulum to the greater ischiadic notch. 



The resultant plane xi/ passes through the body of the 5th lumbar 

 vertebra, and between the spinous processes of that vertebra and the 

 first sacral vertebra. * 



■Anterior 3fuscles of Sip Joint. 



The first eight of the ten anterior muscles have the following 

 action : — 



1. Iliacus, \ 



2. Psoas magnus, > 4| oz. 



3. Psoas parvus, ) 



move the head of the femur in the plane a^, which is found to be the 

 prolongation of the diameter a ; and their action therefore is directly 

 the opposite of that of the glutceus maxlmus. 



4. Pectinseus, . . . 



5. Adductor longus, 



I 2h oz. 



move the head of the femur in the plane containing the ilio-pectinseal 

 ridge, or very nearly in the plane of the resultant moment of the glutcei 

 muscles. 



6. Adductor magnus, | - „ 



7. Adductor brevis, j 



produce motion alone the line l', which is opposite to h, the direction of 

 th.Q glutceus medius. And, lastly, the 



8. Gracilis, 1 oz. 



moves the head of the femur in the plane c\ opposite to c, the direction 

 of the glutceus minimus. 



* It was through this notch that Meriones was in the habit of piercing the bladders 

 of his flying enemies ; II. E. 65-68, and II. N. 650-655 ; and the bone mentioned is the 

 ilium, and not the puhes, as the commentators suppose. It is very possible that 

 Homer may have seen such a wound inflicted through the buttock, for his description 

 of the wounded man, wriggling on the ground like a worm, after the division of the sci- 

 atic nerve, could only have occurred to an eye-witness. 



E. I. A. PEOC. VOL. VIII. 3 Q 



