142 



THE CAPILLAEIES. 



possesses a certain degree of elasticity, and presents here and there cell 

 nuclei. 



Fig. 61. Fig. 62. 



Capillary distribution to mucous membrane of 

 stomach. 



Capillary distribution to villi of duodenum. 



Fig. 63. 



The interspaces between adjacent capillaries vary much in size and 

 Size of inter- shape, the latter variation being dependent on the mode of 

 spaces. distribution, whether parallel, reticulated, looped, &c. ; as to 



size, in the liver the interspaces are of less diameter than the capillaries, 

 in the choroid coat still smaller, but in the cellular coat of the arteries 

 they are ten times larger than the vessels. These interstitial spaces are 

 nourished by the matter which exudes through the thin walls of the cap- 

 illaries. 



Fig. 63 represents 

 the capillary circula- 

 tion in the web of the 

 frog's foot : a, venous 

 trunk ; , #, branches 

 of venous trunk ; c, c, 

 pigment cells. The 

 elliptical blood- discs 

 are seen in outline in 

 the interior of the ves- 

 sels. 



The blood flows 

 through the capilla- 

 ries in an uninterrupt- 

 ed stream, its jetting 

 motion being entirely 

 lost. The rate of cir- 

 culation through the 



Capillary circulation of frog's foot. SVStemic Capillaries is 



