GLOSSARY XI 



Exotoxin. A soluble bacterial toxin which is excreted by the bacterium into 

 the surrounding fluid during the life of the organism. 



Fixation of complement. A synonym for Bordet's phenomenon, q.v. 

 Fixator. A synonym for immune body or amboceptor. 



Gastrotoxin. A cytotoxin or cytolysin acting on the cells of the mucous 



membrane of the stomach. 

 Gengou's reaction. The removal of all alexin or complement from a fluid by 



means of a compound of a precipitin and its antigen ; analogous with 



Bordet's phenomenon, except that in this case the reacting antigen is a 



soluble substance. The two are often grouped together as the Bordet- 



Gengou reaction. 

 Group reaction. A reaction with an antibody (usually an agglutinin) which 



is common to several species of bacteria, forming a well-defined group 



e.g. , the coli group, or the pasteurelloses. 



Haemagglutinin. A substance which agglutinates red corpuscles. 



Hsemolysin. A substance which dissolves red blood-corpuscles, or at least 

 releases the haemoglobin which they contain. The term is used mainly 

 for an antibody having, in conjunction with alexin, a solvent action of 

 this nature. 



Haptin. A portion of a molecule of protoplasm having combining affinities 

 for food molecules, and forming an antibody when shed (v. Receptor). 



Haptophore group, or Radicle (CCTTTW, I fasten). That portion of a substance 

 (whether antigen or antibody) which has the power of entering into com- 

 bination with its appropriate antibody or antigen, as the case may be. 

 Thus a molecule of toxin is supposed to contain a group of atoms which 

 can combine with a cell or molecule of antitoxin, and a second which can 

 then exert a toxic action. The former is known as the haptophore 

 group. 



Immune body (immunis, exempt from public service). A specific antibody, 

 produced by the injection of bacteria or other cells, and having the 

 power of altering these substances in such a way as to render them com- 

 pletely or partially soluble on the addition of alexin. It is the same as 

 amboceptor, but the term implies no theory and is generally preferable. 

 Synonyms : substance sensibilatrice, desmon, preparator, copula, etc. 



Incitor constituent of serum. A substance which aids phagocytosis, espe- 

 cially thermostable opsonin. 



Isoagglutinins. An agglutinin which, ' occurring in the serum of a certain 

 animal, will agglutinate the red corpuscles of other animals of that 

 species, but not those of the individual which produces it. 



Isohsemolysin. An immune body or amboceptor which, occurring in the 

 serum of a certain animal, dissolves (in conjunction with alexin) the red 

 corpuscles of other animals of that species, but not those of the individual 

 which produces it. 



Koch's phenomenon. The tuberculin reaction, or rise of temperature and 

 sudden exacerbation of the local lesions occurring in a tuberculous animal 

 after injection of a culture of tubercle bacilli, living or dead, tuberculin, 

 or other specific tuberculous material. 



Lactoserum. A serum containing a precipitin for milk proteids. 



Leucotoxin. An antibody (immune body or amboceptor) which, in conjunc- 

 tion with alexin, exerts a toxic influence on leucocytes. 



Lysis (Xims, a loosening). The solution of cells, bacteria, etc., mostly by 

 means of antibodies or other protective substances. 



LO dose of toxin. The amount which is exactly neutralized by one unit of 

 antitoxin. 



L+ dose of toxin. The amount which, added to one unit of antitoxin, behaves 

 just like one lethal dose of toxin, bringing about a fatal result in test 

 animals within the time-limit fixed. The fact that the L_|_ dose -the L 

 dose is greater than one lethal dose constitutes the Ehrlich phenomenon. 



