1901.] Properties of the Arterial and Venous Walls. 135 



The general character of the tracing is not altered in the aorta and 

 pulmonary artery or in the relaxed carotid, though the actual amount 

 of stretching is much increased, especially with the first weight or two. 

 (Figs. 12, 14, 15, and 16.) 



Fig-. 14. — Pulmonary artery (sheep). Transverse strip. Loaded a seond time 

 after an interval of 7 minutes. 



FiQ-. 15. — Pulmonary artery (sheep). Logitudinal strip. Loaded again after an 

 interval of 7 minutes. 



Contracted Arteries. — Transversely cut strips of contracted artery 

 yield remarkable results, entirely different from those just described. 

 Equal increments of weight cause increments of elongation, relatively 

 small at first, and increasing in magnitude up to a maximum, beyond 



