THE MAMMALIA OR MAMMALS. 



43 



capillary vessels which connect the termination of the arte- 

 ries with the beginning of the veins.* Their blood is warm, 

 and the red corpuscles are non-nucleated (Fig. 35). 



Their respiratory system consists of lungs suspended in 

 a cavity called the chest, and which is separated from the 

 cavity of the abdomen by a muscular partition called the 

 diaphragm. 



The motatory system of the Mammals consists of mus- 

 cles, tendons, and ligaments, together with the solid skele- 

 ton to which these are attached. 



* Some idea of capillary circulation in general, may be obtained from the 

 accompanying highly magnified particle of the web of a Frog's foot. 



FIG. 53. 



Or" 



Minute portion of the web of a Frog's foot. Showing capillary circulationthe blood 

 disks plainly seen in the capillaries. Highly magnified. 



a, trunk of a vein; &, b, &, capillaries; c, c, pigment cells. 



