116 LIVERPOOL BIOLOGICAL SOCIETY. 
fluid ejected from it passes into b, a strong, wide rubber 
tube; with this is connected a manometer c, and a 
length of thinner rubber tube d. These, as in the ordinary 
blood schema, represent the heart and arteries. The tube 
d, is connected with the glass tube e, which passes through | 
the cork of the wide-mouthed bottle, and is connected 
at its other end with the narrow rubber tube f; this is 
perforated by numerous pin-holes so as to render it 
permeable. The other end of /, is connected with the glass 
tube g, which is either narrower than e, or constricted 
at its lower end; in this way it offers a slight resistance — 
to the onward flow. g, ends in a piece of rubber tube h. 
j, stands for the capillaries, and g, h, for the veins. 
Opening freely into the bottle by its lower end is the 
tube 7, which is attached above to the glass tube &. 
This perforates the cork and ends in the rubber tube J. 
i, k, l, represent the lymphatics. | 
Perforating the cork also is the manometer tube m, for 
measuring the pressure in the bottle—the lymph pressure, 
or extra-vascular blood pressure. 
When fluid is driven intermittently into the system 
by squeezing the ball a, the tubes 0, and d, become 
distended, the manometers show a rise in pressure in the 
system, and a continuous flow of fluid comes from h, and 
1, rapidly from h, slowly from J. 
When the fluid in its passage reaches /, the artificial 
permeable capillary, some will pass through its walls into 
the cavity of the bottle, representing the tissue interspaces. 
It there causes a rise of pressure, which is recorded by 
the manometer m. The fluid as a consequence of this 
rises up the tube 2, k, 1, and flows out at J. 
In order to better represent the cells and tissue inter- 
spaces, | have sometimes filled the bottle with pebbles or 
coarse sand. 

