■I."),; Frocccdinys of the Ohio State .Icadcmy of Science 



iiitc) the cell substance directly. The body cells of the higher 

 forms are specialized and cannot digest food for themselves. 

 'They are suspended in the body fluid, the lymph, in. exactly 

 the same sense as the amoeba, the dilTerence being that these 

 cells can not go after their food like the amoeba which may 

 move about in the water from poorer to richer feeding 

 grounds, but their food must be pre^:a'.ed and brought to them 

 by the circulation of the Huid .n which they are suspended. 

 The blood circulates in a clc.sed system of vessels and does 

 not bathe the cells in general, but the lymph or body fluid has 

 its origin mainly in the blood b}- dializing through the walls 

 of the capillaries and bathes the cells of the body. The cir- 

 culating media of the body carry on a double function. The 

 distributing of the food has alreadv been mentioned but the 

 other side, the carrying the waste from the cells is as neces- 

 sary to the life of the body as the food supply. Activity means 

 waste in every place so every living organism is constantly 

 producing matter that must be eliminated. The cells can not 

 get away f re m it th.erefore it must be carried from the cells. 

 If the cells can n.;t get the foi^l necessary and can not get 

 rid of the waste matter, first they will starve and secondly 

 they will be choked and death will be the result in either case. 

 The bodv as a whole is alive or dead in proportion to the 

 number of cells that are living or dead. The main point here 

 is the absolute i:ecessity for a circulatory medium and that 

 this medium be kei)t in motion manly on account of the s])e- 

 cialized condit'on and the size of tlie human l)ody. Small 

 l)odies like the amoeba can come in contact on all sides with 

 the food, but with large bodie-^ it is not st). To satisfy these 

 conditions the blood must l)e i)Ut under pressure in the ar- 

 teries. This pressure must be ke])t up and the arteries full 

 of blood all the time. These conditions being mantained the 

 blood will circulate to the points of least resistance. The re- 

 sistance Vvill denend ui)on the activity of the organ or organs 

 in cjuestion. This wdl inckrle muscular activity, glandular 

 activitv. etc. Anv acti\it\ will force tlu- blood c.vX of an or- 



