292 



SELLARDS. 



Table III. — Lysis of amoebce by. heated sera. 



■ 



■ - ' 



Dilution. 



Serum 



formerly 



immune to 



amoebse. 



Control, 

 normal 

 rabj)it. 



Coiitrol, unheated . 



1 '"' 



1-5 



I 1-10 



1 1-5 

 i 1-10 

 , 1-5 

 I 1-10 



\ 1-^ 

 I 1-10 



) 



None. 

 None. 

 None. 



■ Active. 

 None. 

 None. • 

 Active. 

 NOne. 

 Active. 

 None.,; 



None. 

 None. 

 None. 



Active. 



None. 



None. 



None. 



None. 



None. 



None, 



Serum heated for one hour at— 



60° C . 



- 70° C 



78° C_- _ . 





This result shows definite activity of the normal serum when heated' 

 at 60° and of the immune serum at 60°, 70°, and 78° C. ^ 



An additional test was carried out to determine whether this^ apparent 

 difference between the normal and immune sera at higher temperatures 

 is a specific property of anti-amoeba sera or whether it is common to 

 other immune sera. The sera of a rabbit immune to Y. cliolerce was 

 used and a second rabbit formerly immune to amoebae also tested in 

 addition to the one used in the preliminary experiment. The results 

 are given in Table IV. ■ 



Table IV. — Lysis of amoebce by heated sera.* 



• 



Dilution. 



Serum formerly im- 

 mune to amoebse. 



Serum im- 

 mune to 

 V. cholerse. 



Controls, normal 

 rabbit serai. 



A. 



B. 



'AV ■ 



B. 



Control unheated 



1 - 



I 1-10 



1-2 



1-5 



I 1-10 



. 1-5 



I 1-10 



1 '-' 

 \ 1-10 



None. 

 None. 

 None. 



Active. 



None. 



None. 



Active. 



None. 



Active. 



None. 



None. 

 None. 

 None. 



Nbne. 



None. 



None. 



Active. 



None. 



Active. 



None. 



None. 



None. 

 None. 



Active. 



None. 



None. 



None. 



None. 



None. 



None. 



None. 

 None. 

 None. 



Active. 

 None. 

 None. 

 None. 

 None. 

 ' None. ■ 

 None. 



None. 

 None. : 

 None. 



Active. 

 None. 

 None. 

 , None. 

 None. 

 None. 

 Noiie., 



Serum heated for one hour at— 

 60° C - 



70°C ........ 



78° C 





*The word lysis has been retained in speaking of the action of the serum on 

 the amoebae although the process, at least in the case of the heated normal serum, 

 differs from that of the ordinary specific lysins. With an immune serum some 

 solution takes place within the first few hours and although a period of eighteen 

 or twenty-four hours may be required to complete the process, yet it is accom- 

 plished by a direct action on the amoebae and it is not a secondary effect of the 

 action of the antibacterial serum on the accompanying bacteria. Apparently the 



