52 MATERIALS FOR A MEMOIR OX 



ward movement is secured by the front limbs, and that the hind 

 limbs remain the same. (See p. 42.) 



In the sloth the foot is lifted as well as swung. (See Fig. 11, 

 p. 83.) It would be interesting to ascertain if the ape also lifts 

 the limbs in swinging. 



All elements of the swing of the hind limb appear to be lost 

 in the "jump" if the two hind feet act synchronously. 



In the camel the fore foot in backward strain answers to a ver- 

 tical line which intersects a point as far back as the middle of the 

 posterior dorsal hump, while the hind limb advances forward as 

 far as the concavity between the humps. (See p. 38.) 



The Degrees made by the Limbs at the Extremes of Forward and 

 Backward Movement. 



The fore limb when at the extreme of forward movement pre- 

 sents an axis which is very oblique as compared to the limb when 

 in the perpendicular position. Again, when in the extreme of 

 backward movement it is again oblique to the same perpendicular 

 position. It has been thought of sufficient interest to record the 

 exact degrees presented by these extremes of movement in the 

 fore limb and to contrast them with similar movements of the 

 hind limb. 



By the use of the word plus, or the plus sign (+), a deviation 

 to the right of the vertical is indicated. In like manner minus, 

 or a minus sign ( — ), indicates a deviation to the left. 



In the elephant (series 733, Fig. 13) the forward strain of the 

 fore limb is 25° minus. The backward strain is 35° plus. In the 

 hind limb (Fig. 10) the forward strain is 15° plus and the hind 

 strain (Fig. 9) is 45° minus. In the lioness (series 728, Fig. 3) the 

 forward strain is 50° and the backward strain 20°. In the hind 

 leg the forward strain is 50° and the backward strain 50°. 



In the dog (series 707, Fig. 1) the fore foot at the end of back- 

 ward strain, but as yet on the ground, is in an axis of 10° minus; 

 the rest of the limb being 20° plus nearly. In Fig. 2, the foot 

 having left the ground, marks 80° minus, nearly, while the rest 

 of the limb remains nearly the same as when on the ground, — 

 namely, 18° plus. In the hind leg, as in Fig. 5, the foot when 

 at the end of backward strain gives an axis of 90° minus ; while 

 that of the metatarsus gives 10° minus ; and that of the thigh is 



