OF THE MUSCULAR SYSTEM IN GENERAL. 429 



each other, to produce contrary actions: in the first case, the 

 muscles are called congeneric; in the second antagonist. An- 

 tagonism is much the most evident in the exterior muscles, 

 as, for instance, it is seen in the flexors and extensors; it is 

 less strongly marked in the interior or automatic muscles; 

 nevertheless, it is not altogether foreign to them; 'opposition 

 of the automatic and arbitrary muscles occurs at the natural 

 orifices, as is perceived between the excretory muscles, which 

 are involuntary, and the sphincter muscles which are volun- 

 tary. Antagonism every where presents this remarkable phe- 

 nomenon, that the Contraction of some muscles is accompanied 

 by the relaxation of another. The Congeneric or associated 

 muscles present another important phenomenon, which is, that 

 their contraction is simultaneous, and that, when a stimulus 

 is confined to one only, the rest nevertheless come into action: 

 thus when the throat, the orifice of the larynx, the anterior 

 angle of the vesical trigon, &c., are stimulated, all the muscu- 

 lar powers exercised in vomiting, in coughing, or in urinat- 

 ing, &c., are brought into action by the law of association 

 of the congenerous muscles, but at the same time aixl in con- 

 formity with the law of antagonism. In the last case the 

 sphincter and constrictor muscles of the neck of the bladder, 

 and of the ureter, are relaxed. 



687. The muscles continue, some time after death, and 

 after circulation ceases, to be irritable and contractile by means 

 of divers stimuli. All the muscles do not preserve their irri- 

 tability during the same period; neither do they suddenly lose 

 their susceptibility to contraction, but cease at first to be e- 

 citable by certain stimuli; the anterior state of health, the kind 

 of death, the exterior circumstances before death, have a great 

 influence on the duration of the muscular irritability. Galen, 

 Harvey, and Haller, knew that the heart is in general the 

 ultimum moriens. Haller had established an order of cessa- 

 tion of irritability in the different muscles, and also perceived 

 several varieties in -that order. Zinn, Zimmermann, Ader, 

 Froriep, and particularly Nysten, have particularly studied 

 this subject. The varieties perceived by Haller, depend 

 greatly on the nature of the excitant; for instance; the heart 



