278 INFECTION AND IMMUNITY. 



and designates the albumin fraction as comple- 

 ment "end-piece." 



The end-piece, middle-piece and amboceptor 

 bear the same relation to each other as whole 

 complement amboceptor and antigen. 



The middle-piece is thermostabile when attached 

 to the amboceptor antigen complex, but thermo- 

 labile when heated alone or in combination with 

 the end-piece. The end-piece is thermolabile. In 

 specific complement deviation,, it is the middle- 

 piece which becomes bound, the end-piece remain- 

 ing free. 



Attempts to ascertain the nature of these two 

 parts by substitution of lecithin and other lipoids 

 have so far been without result in explaining the 

 nature of the two components (Lief man and 

 Cohn). 



