WORK OF THE THYSIOLOGICAL STATION AT PARIS. 



405" 



But I can not enter into detail regarding these special comparative 

 studies which show analogies and differences between various species 

 of animals in accordauce with their anatomical structure. 



The absolute fidelity of these chrono-photographic outlines allows us 

 to estimate the value of certain analyses of the movements of limbs 

 made by different authors. The most exact are certainly those of Vin- 

 cent and Goiftbn, We can not too greatly admire the sagacity of these 

 authors who have given so faithful a representation of the movements 

 of tlie horse in slow gaits. 



Finally, these same pictures permit us to determine the action of cer- 

 tain muscles at different phases of the gaits. By starting from the suc- 

 cessive attitudes of the limbs we reach the physiological mechanism of 

 the movements under consideration. 



J?1G. 3.— Attitudes aud succt-sisive ])ositi()ii8 oftlu; riiilit hind let;- <if a wheel) ddiiiig :i stei> iu walkinji. 

 The dotted Hues show the positioua of the left liiud U-j^. 



. The sagacity of physiologists has often been tried by these obscure 

 questions. Maissiat ' more than anyone else has attempted to eluci- 

 date the part played by muscles in the walk of man. He has done in 

 this respect all that can be done by subtle observation joined to a pro- 

 found knowledge of the laws of mechanics. 



But in questions of this kind the keenest intelligence can not attain 

 the precise results that are obtained by an exact method. Already, by 

 using localized electrization, Duchenne, of Boulogne, has shown in 

 man the special functions of the individual muscles; he has shown that 

 in the various acts of locomotion the uuiscles are associated by groups, 

 synergistic or antagonistic, and that each movement is a resultant of 

 these combined forces. 



More powerful methods allow us to now elucidate these questions. 



Upon the photographs of an animal in motion we may mark the 

 origin and insertion of muscles which we have learned from our ana- 

 tomical specimens, and, joining these insertions by one or more marks, 



' Jacques Maissiat, fitiides de physique auimale, 4'^, Paris, 1843. 



