Complement-Deficient Guinea Pigs. 71 



growth. The addition of comb honey, however, brought about 

 cessation of decline and distinct gains in weight. 



The addition of twenty per cent, of honey to the diets of guinea 

 pigs did not prevent, or appreciably delay, the development of 

 scurvy in these animals. 



33 (16x5) 



A study of the serum of complement-deficient guinea pigs. 

 By Arthur F. Coca. 



[From the Laboratory of the New York Hospital.] 



H. D. Moore 1 has described a race of guinea pigs that are 

 naturally deficient in complement: the deficiency is inherited. 

 A number of these animals were obtained from Dr. F. A. Rich of 

 the Vermont State Agricultural Experiment Station and the sera 

 of four were separately examined as to the presence of the com- 

 ponents of complement. The findings were identical in all of the 

 sera. 



Both the mid-piece and the end-piece of complement are 

 present. There is lacking only the so-called "third-piece," which 

 is the thermostable element of complement that is destroyed by 

 cobra-venom and absorbed by yeast cells and bacteria. 



By itself, the complement-deficient serum produces no hemoly- 

 sis when used in a quantity 40 times that of the minimal completely 

 heomlytic quantity of normal serum. When mixed with a small 

 quantity of inactivated normal serum (guinea pig or human) the 

 complement-deficient serum hemolyses in about three times the 

 minimal hemolytic quantity of normal guinea pig's serum. 



The third piece of complement is not identical with the lipoid 

 cytozyme (thrombokinase), since the blood of the complement- 

 deficient guinea pigs clots normally. The third piece of comple- 

 ment is not absorbed out of normal serum by six volumes of ether. 



1 Journal of Immunology, 1919, iv, 425. 



