Concentration of Dyes in Plasma 227 



fifth of the time required by the latter. The length of the lethal 

 dose of radiations for these two forms is about in the same pro- 

 portion. 



It can be shown that one of the physical effects of the radia- 

 tions is to increase the permeability of the cells by injuring the 

 cell wall. If the treatment is long enough continued the cells 

 cytolyze completely. From this it follows that when cells are 

 already highly permeable, as they are during growth and division, 

 complete cytolysis quickly ensues : whereas when the cell mem- 

 brane is relatively impermeable, as it is in resting cells, radiation 

 must be long continued before destructive cytolysis can be ob- 

 served. 



Abstracts of Communications, Minnesota Branch 



Ninth meeting. 



Minneapolis, Minnesota, January 10, 1923 



110 (2070) 



The effect of increase of blood pressure on the concentration 

 of colloidal dyes in the plasma. 



By F. H. SCOTT, M RABINOWITZ. and A. RUPP. 



[From the Department of Physiology, University of Minnesota, 

 Minneapolis, Minnesota.) 



Great changes in the number or volume of the corpuscles, or 

 in the haemoglobin content of the blood may occur in a very 

 short time. In using corpuscles or their derivatives as the in- 

 dicator of the concentration of the blood one meets with the 

 objection that there might be hidden masses of corpuscles ready 

 to be put into the circulation in times of stress. No evidence 

 exists for such masses of corpuscles and it is well known that 

 dilution of the blood may take place equally as rapidly as con- 

 centration. In the case of the dilution caused by haemorrhage 



