98 MATERIALS FOR A MEMOIR OX 



ground, but would simply hold the ends of the toes firmly to the 

 plane on which the animal is moving. The toes are also markedly 

 abducted in the same position. The attitude taken by the human 

 fore limb is precisely that of the fore limb of the quadruped en- 

 gaged in terrestrial progression, and is modified in its action solely 

 by the circumstance that it " claws the air." The function of the 

 interossei would appear to be the retention of the phalanges of the 

 terminal row against the ground as the last act of the behavior of 

 the foot in the first stage of the recover. 



Second, that the occurrence of convulsive seizures, in which the 

 limb assumes the position just described, may not necessarily be 

 the result of an irritation of the centres which control the co-or- 

 dination, but an evidence of a profound irritation elsewhere in the 

 economy. This phenomenon properly belongs to the group of 

 influences described by Drs. Mitchell and Lewis.* 



To a still greater extent than in the quadruped the superficial 

 muscles are conspicuous. It is of interest to note that the sartorius 

 muscle may be tense even when the foot is on the ground, as is 

 observed in the figure of a man lifting a weight (series 322, Fig. 

 12). In various attitudes the several portions of the trapezius 

 muscle are contracted. In series 323, Fig. 9, in the figure of 

 a man engaged in lifting a dumb-bell, the upper portion of the 

 dorsal division of the muscle is enormously enlarged. 



Oscillation. 



The single series designed to illustrate the movements of the 

 pelvis in walking is not in all respects satisfactory. 



Since the index at first inclines to the right side, which corre- 

 sponds to the limb which is off the ground, the idea is at once 

 sucfo^ested that the inclination is ijreatest towards the side not bear- 

 ing weight, especially when it is noted that the index is vertical 

 and parallel to the vertebral column when the legs are both on 

 the ground. But when the left foot is lifted the lever remains in 

 the vertical position, and no definite conclusion as to the effect 

 of the movements of the limbs on the oscillation of the level is 

 determined. 



* Philadelphia Medical News, 1885, vol. xlviii. p. 169. 



