CAPILLARY CIRCULATION. 



53 



The Circulation of Blood in the Web of a Frog's 

 Foot. For this get a frog with a pale web. Take a piece 

 of shingle six inches long and three inches wide. Cut a 

 round hole, half an inch in diameter, near one end of it. 



Walls of Capillaries 



Tissues of Web 



Fig. 17. Part of Frog's Web (highly magnified). 



