CHAP. IX.] 



THE CONTRACTILE TISSUES. 



377 



defibrinated blood undergoes as it is artificially forced in a constant 

 stream, through separated though still living muscles. For this purpose 

 the biceps and semitendinosus muscles of the dog's hind-limb may be 

 employed. These muscles are supplied with blood by a branch of the 

 hypogastric artery, and by three or four branches indirectly from the 



FIG. 59. APPAKATUS OF LUDWIG AND A. SCHMIDT. 



TT is a glass vessel containing the muscles B, resting upon a support G ; the upper 

 edge is ground, and smeared with grease, to permit the hermetical closure of the vessel 

 by means of a glass plate. 



Q is a glass vessel containing mercury, resting on blocks r, r: by raising Q the 

 blood in F may be driven through the vessels of the muscles in T. 



F is a, vessel containing blood. 



A connects the vessel F with the blood-vessels of the muscles under experiment. 



V conducts the venous blood from the muscle. 



R, R' are two graduated pipette-like vessels connected by means of a flexible tube 

 and containing mercury. Venous blood flows into R, displacing the mercury. 



E, E, electrodes. 



M, M, mercurial manometer. 



femoral artery. Cannulae should be tied into the hypogastric vessel 

 and into the main branch from the femoral vessel, and all the arterial 

 twigs going to neighbouring parts should afterwards be carefully liga- 

 tured. A corresponding number of cannulae should be introduced into 

 the chief veins. The muscles may then be separated from the surround- 

 ing tissues, a portion of the tuber ischii being sawn off with their origin. 

 The two arterial cannulae are connected with the two limbs of a 

 T-tube of glass, the third limb leading to the reservoir which contains 

 the blood. A similar arrangement connects the two veins with a vessel 



