EFFECT OF LIGATURE 305 



conduct excitation applied at a distance, and thereby induce 

 a modification in the pulsating activity of the attached 

 leaflet, is one of very great importance. This question will 

 be taken up in a succeeding chapter. 



Summary 



Increased hydrostatic pressure induces an expansive 

 erection of the leaflet of Desmodium gyrans. The enforced 

 expansion induces a diminution in the extent of systolic 

 contraction. 



Increasing load induces a diminution of amplitude and 

 prolongation of period of pulsation. A load of ? V grm. is 

 enough to arrest the pulsation. 



A ligature applied 3 mm. below the motile organ arrests 

 the pulsation of Desmodium leaflet at diastole. This cor- 

 responds to the action of Stannius' ligature on the heart. 



A cut also arrests the pulsation of Desmodium. After the 

 arrest, pulsation may sometimes be revived by the action 

 of an electrical shock. 



