1894.] 



NATURAL SCIENCES OK I'HILiADELPHIA. 



173 



tiii'liteuing of the rubber biuids representing all the principal muscles, 

 both the so-called tlexors and the so-called extensors, «Y tlw suinetline, 

 caused the upper part of the limb to spring forward when released, 

 and proved to me that I was not mistaken in my observation on the 

 living horse. 



Returning to the dead horse, I denuded both a front and back leg 

 of every shred of muscular fibre, yet they sustained weight. 



There was no tendency to collapse, and an increase in the weight 

 only njeasured an increase of resistance. " (If one wishes to rejjeat 



my experiment with the dead 

 horse and should choose the 

 front leg, he must respect the 

 large tendon concealed in the 

 biceps brachialis which might 

 escape a careless dissection, 

 especially by one accustomed 

 rather to dissections of the 

 human body. ) Observation 

 of the living horse will teach 

 us, that, if he wishes to lie 

 down, he must first flex the 

 pasteiui, and the stumbling 

 horse must strike the hoof 

 with force enough to flex the 

 phalanges before he can go 

 down. 



To illustrate in the simplest 

 way the scheme of the muscles 

 and tendons passing more than 

 one joint I pivoted one little flat stick upon two others (fig. 1), and 

 on the horizontal sticks I drove in four pins leaving the heads pro- 

 ject slightly, the pin a close to the upper joint, the pin b farther from 

 it ; the pin d close to the lower joint, the pin c farther. If two in- 

 extensible strings be looped, one from a to c, the other from b to (/, 

 the upper horizontal piece is held up and will sustain weight. The 



Fig. 1. 



■'' Mr. Eakiiis exhibited to the members of the Academy photographs made by 

 him at tlic University of Penusylvauia in 1SS3, showing the front and l)ack leg of 

 a dissected horse, all the muscles having been removed. Nevertheless the limbs 

 sustained M'eight. H. Allen. 



