164 



Scientific Proceedings (60). 



three animals again tested on the first, second and sixth day after 

 this bleeding. 



For the sake of brevity the complete data obtained with the 

 salt solutions are not given but only the point of beginning he- 

 molysis and of complete hemolysis. They are as follows: 



TABLE II. 





Sheep T. 





Date. 



Hemolysis begins. 



Hemolysis complete. 



April 22 



.600 



.400 



April 23 



•575 



.400 



April 24 



(•525) 



.400 



April 28 



•575 



.400 





Sheep F. 





April 22 



.600 



•450 



April 23 



•575 



•450 



April 24 



(.525) 



•450 



April 28 



•575 



•450 





Sheep P. 





April 22 



.700 



•525 



April 23 



•675 



.500 



April 24 



( ) 





April 28 



.650 



•525 



It is seen that hemorrhage had practically no effect on sheep 

 T (the variations are within the range of experimental error). 

 The resistance of each animal was about the same on each day. 



The cells on each day were also again tested with amboceptor 

 and complement and without giving charts of the results it may be 

 stated that the differences between the three sheep were sub- 

 stantially the same as they were before the bleeding of sheep T on 

 each of the four days. 



It is interesting to note that the resistance to immune serum 

 on each day ran parallel to the resistance to hypotonic salt solution, 

 the cells of sheep P always being most easily laked, those of sheep 

 F next and those of sheep T least easily laked. 



We also attempted to determine whether the differences in 

 susceptibility to laking by immune serum were due to differences 

 in ability of the different sheep's cells to absorb amboceptor. 

 This was found not to be the case: at least the cells of all three 

 sheep were able to absorb a great excess (at least 30 units) of 



