THE THIGH. 201 



The third bone difFers in nothing from the description of the 

 third hone of the thumb, except in the general distinguishing 

 marks ; and, therefore, the second and third phalanx of the 

 fingers enjoy only flexion and extension. 



All the difference of the phalanges of the several fingers 

 consists in their magnitude. The bones of the middle finger 

 being the longest and largest ; those of the /ore-^n^er come next 

 to these in thickness, but not in length, for those of the ring 

 finger are a little longer. The Jiitle finger has the smallest 

 bones. This disposition is the best contrivance for holding the 

 largest bodies ; because the longest fingers are applied to the 

 middle largest periphery of such substances as are of a spherical 

 figure. 



The Inferior Extremities. 



The inferior extremities consist of the Thigh, Leg, and 

 Foot. 



The Thigh 



Consists of one bone only ; the os femoris, which is very 

 strong, and larger than any other in the skeleton. It is nearly 

 cylindrical in the middle, and slightly curved. The upper 

 extremity is a spherical head, connected to the body of the bone 

 by a neck. The lower extremity is much larger than the body, 

 and is formed into two condyles. 



The upper end of this bone is not continued in a straight line 

 with the body of it, but the axis of it inclines obliquely inwards 

 and upwards, whereby the distance between these two bones, at 

 their upper part, is considerably increased. The head is the 

 greater portion of a sphere. Towards its lower internal part, 

 a round, rough spongy pit is observable, where the strong 

 ligament, commonly, but inaccurately, called the round one, is 

 fixed, to be extended from thence to the lower internal part of 

 the receiving cavity, where it is considerably broader than near 

 to the head of the thigh bone. The neck of the os femoris has 

 a great many large holes, into which the fibres of the strong 



