328 A Manual of Veterinary Physiology. 



ligaments and tendons are held to be non-elastic, yet 

 we must claim for the suspensory ligament a little more 

 elasticity than would be obtained if the sesamoids were 

 united by bony tissue to the metacarpal ; and the pleasant- 

 ness and freedom from jar experienced in the riding-horse 

 is due to the suspensory ligaments. But Stillman 

 claims for it a function which he believes to be demon- 

 strated by instantaneous photography, viz., that it acts the 

 part of a spring, flexing the fetlock sharply when the weight 

 is taken off it, and explaining why the dirt is thrown out of 

 the feet of a galloping horse. The sharp picking up of the 

 foot from the ground in walking (a movement so rapid as 

 almost to defy detection) is probably assisted by the sus- 

 pensory ligament. Besides these functions, the suspensory 

 ligaments assist the horse to stand whilst sleeping. 



Function of the Check Ligaments.— Horses are enabled 

 to sleep standing, and remain for some considerable time 

 without lying down, by means of a singular arrangement 

 of check ligaments which exists in both fore and hind 

 limbs. The flexor tendons support the weight, the ex- 

 tensors keep the limbs rigid. In order that the strain of 

 supporting the weight may not be placed on the muscles 

 of the arm, both flexor tendons, one above and both 

 below the knee, receive a large branch of ligament from the 

 radius and metacarpus respectively. These are attached 

 below the muscular portion, and so cut off the latter 

 entirely from the strain of standing in one position for any 

 length of time. This is also assisted by the suspensory 

 ligament running from the metacarpus to the back of the 

 fetlock. If the suspensory ligament be divided, the 

 fetlock does not come to the ground : if the perforans be 

 divided, a slight sinking of the fetlock is the only change. 

 To bring the fetlock to the ground, both flexors and sus- 

 pensory ligament must be divided, which demonstrates that 

 all three support the weight while standing, and by their 

 peculiarity in attachment enable the animal to sleep in the 

 upright position. 



Further, the horse is enabled to stand whilst sleeping by 



