APPENDIX. 455 



boue, it will also be observed that the attachments of the homo- 

 logu.es of the inferior spinatus and teres minor retain their attach- 

 ments to the great trochanter. 



It becomes, therefore, an important question to determine the 

 homologies of the humeral tuberosities and femoral trochanters. 

 With this view it is to be observed, that as the obturator internus 

 would appear to be the real homologue of the subscapularis, and 

 as the tendon of the obturator internus is attached to the fore-part 

 of the upper margin of the trochanter major, it follows, that if we 

 are to be guided as to the homologies of the tuberosities and tro- 

 chanter by the principal homologous muscles connected with them, 

 the trochanter major, instead of being, as is usually supposed, the 

 greater tuberosity of the humerus, must be the homologue of the 

 lesser tuberosity, and the lesser trochanter the real homologue of 

 the great tuberosity. If this be admitted, then we must also admit 

 that the homologue of the centre of ossification of the greater tuber- 

 osity of the humerus has been forced downwards, inwards, and 

 backwards, in the direction of the anterior intertrochanteric line, 

 and along with the linear attachment of the clavicular portions of 

 the deltoid and great pectoral, assumed positions on the inner and 

 posterior aspects of the thigh-bone. For physiological ends the 

 attachments of the homologues of the inferior spinatus and teres 

 minor retain their position at the outer and upper part of the bone ; 

 and, in consequence of the homologue of the lesser tuberosity 

 having passed upwards and outwards, so as to take the position of 

 the homologue of the greater tuberosity, these two muscles are 

 secondarily attached to it. 



V.— ACTION OF THE TOPLITEUS MUSCLE. 



This muscle takes its origin below from the tibia and the dense 

 fascia-like prolongation of the semi-membranosus tendon, which 

 covers it. It passes obliquely upwards, forwards, and outwards, to 

 the depression on the outer surface of the external condyle of the 

 femur. Its opposite points of attachment are nearer one another 

 in the extended than in the Hexed condition of the limit. Hence 

 the muscle acts as an extensor, and not, as is usually stated, as a 



