APPLICATIONS TO PHYSIOLOGY 



279 



Action in a Tortoise under Conditions of Artificial Cir- 

 culation. — As we had no large animals at our disposal 

 in which the movements of the heart were accom- 

 panied by such strange variations in appearance, we 

 were compelled to analyze the movements of a land 

 tortoise's heart by means of chronophotography. 



In order that the entire heart might be visible, we 

 removed it from the body and placed it under con- 

 ditions of artificial circula- 

 tion.* Then, in order that 

 the various parts of the cir- 

 culatory apparatus might be 

 confined to as narrow limits 

 as possible, the apparatus 

 was simplified as represented 

 in Fig. 196. 



The narrow end of a glass 

 funnel was introduced into 

 the vena cave close up to 

 the left auricle, and fixed 

 there by a strong ligature. 

 Then a glass canula was 

 introduced into the aorta, 

 and connected with a piece 

 of indiarubber tubing to re- 

 present the artery ; this tub- 

 ing in turn was connected 

 with a piece of glass tubing 

 bent at an angle (o), the 

 opening of the latter was 

 directly above the glass 



funnel. The whole of the apparatus was placed on a 

 solid support, and allowed to stand out in relief against 

 a light background. 



* For the description of the method, see Marey, La Circulation du 

 sang a. Veiat Piiysiologique et dans les Maladies, p. 70, Fig. 28. Paris, 

 G. Masson, 1881. 



Fig. 196. — Heart of a tortoise ui;der 

 conditions of artificial circulation, 

 a, auricle ; », ventricle; a. t., arterial 

 tube; o, outflow; s, support of the 

 funnel, which represents the venous 

 system and its communication with 

 auricle. 



