742 



THE ENDOCRINE ORGANS, OR DUCTLESS GLANDS 



in applying the test. To increase the sensitiveness of the muscle, the 

 artery ring should be slightly stretched by loading the lever. 

 4. The blood vessels of a frog. This method depends on the same prin- 



Funnel, or 

 small pressure 

 borHe 



Hook through 

 lower jaw 



Cannula In 

 one aorfa 



Fig. 192. Arrangement of apparatus for perfusion of the vessels of a brainless frog. (From 



Jackson.) 



ciple as in that just described. The fluid supposed to contain epinephrine 

 is added to Locke's solution, which is meanwhile being perfused under 

 constant pressure through the blood vessels and the rate of outflow 



