November 21, 1902.] 



SCIENCE. 



807 



rivatives. The substances capable of in- 

 ducing this immunizing reaction appear to 

 be mainly of an assimilable, albtiminous 

 nature, or at least intimately associated 

 with such material, although it has been 

 proved that certain non-albuminous deriva- 

 tives of proteids have the same power.* 

 The mode of antagonism of the specific 

 bodies formed in response to the reception 

 within the living organism of substances 

 capable of inducing the necessary reaction 

 varies with the nature of these latter sub- 

 stances, and consists in such diverse mani- 

 festations as neutralization of poisons and 

 of ferments, injury or destruction of cells, 

 associated with characteristic morpholog- 

 ical changes, cessation of motility of cells 

 or their appendages, agglutination of cells, 

 precipitation, and coagulation. In accord- 

 ance with these different effects, the cor- 

 responding antagonistic bodies, or anti- 

 bodies, as they are called, are classified as 

 antitoxins, antienzymes, cytotoxins, agglu- 

 tinins, precipitins and coagulins, and even 

 against these bodies, with the exception of 

 the antitoxins, antagonists have in turn 

 been produced. All of these bodies are in 

 varying, but usually high, degree specific 

 with reference both to the nature and to 

 the source of the material upon which they 

 exert their characteristic effects. 



The C3i:otoxins or eytolysins include not 

 only the bacteriolysins and hsemolysins, but 

 also a great number of other cellular toxins 

 present in the sera of animals which have 

 received injections of cells from a different 

 species. To every cellular group of an 



* Specific precipitins have been produced by in- 

 jection of crystalline and other so-called pure pro- 

 teids. Obermayer and Pick produced immune 

 bodies by the use of non-albuminous products of 

 trjptic digestion of certain albumins. Jacoby 

 has shown that the specific body concerned in 

 ricin immunization is non-albuminous. A. Klein 

 obtained entirely negative results with injections 

 of starch, glycogen, glucose, gum arable and gela- 

 tine. 



animal species there appears to correspond 

 a specific cytotoxin. To designate these 

 various cytotoxins such self-explanatory 

 names as leucotoxin, spermotoxin, nephro- 

 toxin, neurotoxin, thyreotoxin, syncytio- 

 toxin are used. Their specificity extends 

 not only to the nature of the cells, but also 

 to the species of animal furnishing the 

 cells used for their production. 



One of the most important results of re- 

 cent work is the separation of these specific 

 antibodies into two groups, in one of which, 

 represented by the antitoxins, the antagon- 

 ists are single bodies; while in the other/ 

 represented by the eytolysins, the antagon- 

 istic effect requires the cooperation of two 

 bodies. Of these two bodies the one which 

 actually destroys the foreign cells, or in- 

 duces other specific effect, is normally pres- 

 ent in the cells or fluids of the organism, 

 but it seems incapable of action without 

 the intermediation of a body which is dis- 

 tinguished from it by greater resistance 

 to heat, and which is produced by the 

 immunizing reaction, although it may also 

 be normally present in smaller amount.* 

 The two elements composing a cytolysin 

 exist quite independently of each other, so 

 that one may be present without the other, 

 or be artificially removed without affect- 

 ing the other. Of the multitude of names 

 proposed for these cytolytic components 

 those most commonly used for the body 

 which is the specific product of immuniza- 

 tion, although it may also exist normally, 



* Metehnlkoff believes that the complement or 

 cytase, which in his opinion exists under normal 

 conditions solely within cells, not free in the 

 plasma, acts in natural immunity without the 

 cooperation of an intermediary body or fixative, 

 the latter being concerned only in acquired or 

 artificial immunity. The evidence seems, how- 

 ever, to favor the view that in this regard the 

 conditions are similar in both forms of immunity, 

 the main difference being the presence of a much 

 larger i.mount of the specific immuns body in the 

 latter. 



