214 



GENERAL BIOLOGY OF MICRO-ORGANISMS 



Ehrlich explains the formation of cytolysins by the same 

 kind of reasoning as was applied to antitoxins and precipitins. 

 The resulting side-chain would be considered of the same sort 

 as in the latter class of substances, that is a receptor of the 

 second order with a haptophorous group by which to combine 

 with the foreign cell, and a zymophorous group to bring about 

 its solution, were it not for the observed facts given in the experi- 

 ment outlined above, which demonstrate the presence of two 

 distinct substances in the cytolytic complex. A new picture is 

 here necessary and it is furnished by making a joint in the arm 



FIG. 87. Receptors of the third order. (Journ. A. M. A , 1905, J. 1369.) c. 

 Cell receptor of the third order an amboceptor; c, one of the haptophores of the 

 amboceptor with which the foreign body, /, (antigen) may unite; g, the other 

 haptophore of the amboceptor with which complement, k, may unite; /?, 

 haptophore of the complement; z, zymophore of the complement. 



of the receptor of the second order in which the fermentative 

 property is supposed to reside, separating off the zymophorous 

 group as a separate substance and leaving a branched figure with 

 two combining or haptophorous elements, one capable of com- 

 bining with the foreign cell and the other capable of combining 

 with the cytolytic ferment of normal serum and so bringing its 

 action to bear upon that particular cell. The receptor of the 

 third order is called, in accordance with this conception of its 

 relationships, amboceptor, because it acts as a receptor at two 



