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A MANUAL OF BACTERIOLOGY 



Tests may then be done with these strengths of antigen by the 

 " Standardisation of Complement Method," p. 627, and the results 

 of the saline and antigen series compared. 



The anti-complementary power of the antigen may be tested 

 by making a series of tests with the proper antigen dilution with 

 and without a negative serum, using, 1, 1, 2 and 2| m.h.d. of 

 complement. The antigen -f- negative serum should not fix more 

 than about 1| m.h.d. complement. The table below is an 

 example of such a test. 



H = complete, and H = partial, haemolysis. F = no haemolysis. 



The mixtures w r ere incubated for twenty ninutes, the ambo- 

 ceptor-corpuscle mixture was then added, and the mixtures 

 incubated for a further period of thirty minutes. 



Forges' Reaction. If syphilitic serum be added to a solution of 

 lecithin or other lipoid substances, in many cases it gives a white 

 precipitate. Normal or non-syphilitic serum gives no precipitate. 

 This has been tried extensively as a substitute for the Wassermann 

 reaction, but it is not so delicate. 



Class IV. Sporozoa 



The sporozoa are exclusively endoparasitic protozoa, the adult 

 lacking organs for locomotion and for the capture of food, and 

 multiply by some method of sporulation, often very complex. 

 Binary fission is almost unknown in this group. A parasite during 

 the nutritive or " trophic ' ? phase, when it is absorbing nutriment 

 and growing at the expense of its host, is termed a tropliozoite ; 

 when it is mature and ready for sporulation it is termed a sporozoite 

 or schizont. The spores are of various kinds, and may develop 

 outside the body of the host or in a second host. 



