IMMUNOLOGY. IMMUNITY AND IMMUNIZING AGENTS 243 



Fig. 60. — Illustrating cell receptors of the first order. A cell receptor (o) uniting 

 •with the haptophore (c) ot the toxin molecule or antigen. The toxin molecule or anti- 

 gen consists of the haptophore and the toxophore. The toxophore produces the toxic 

 effects upon the cell, e is the haptophore of the cell receptor which has the power of 

 •combining with the toxin molecule thus neutralizing its possible toxic effects. Free-cell 

 receptors constitute the antibodies, and are ever ready to combine with antigens or 

 toxins, should any be present. Cell receptors and antigen bodies are specific in action. 

 The haptophore of the diphtheria cell receptor does not fit the haptophore of tetanus, for 

 example. Bach antigen or toxin reacts •with the antibodies fitted to it. (Journal of 

 the American Medical Association, 1905, p. 955.) 



Pig. 61. — Illustrating receptors of the second order. Fig. 54- illustrating receptors of 

 the first order, c, d,. The cell receptor with a symophore group (d) and a haptophore 

 group (e) capable of combining with disintegrated bacterial substances (/). The zymo- 

 phore group produces a ferment which acts upon (disintegrates) the bacterial cell or 

 blood-corpuscle, as the case may be, seized upon by the haptophore group. (Journal 

 of the Atnericap. Medical Association, 190S. P. Iil3-) 



