222 



ANTITOXINS 



the toxin, and rendering it practically harmless. Antitoxins, therefore, 

 are nothing more than these cast-off receptors, which have a specific affinity 

 for their toxins (Fig. 67). 



As Adami has pointed out, it is probable that the toxins exist for 

 some time within the cell, not as part and parcel of the cell, but as a 

 stimulating agent that causes the cell to develop the habit of producing 

 the specific receptors. The mere union of toxin with a receptor, causing 

 it to fall off, and being followed by nature's mode of repair, with the 

 formation of an excess of receptors and no further stimulation, is hardly 

 sufficient to explain the enormous activity of the cells. 













G 



FIG. 67. THEORETIC FORMATION OF ANTITOXINS. 



That antitoxins may be produced locally was illustrated by the ex- 

 periment of Romer with abrin. This substance has a peculiarly power- 

 ful effect upon the conjunctiva. By gradually immunizing the right 

 conjunctiva of a rabbit with increasing doses, it was shown that, after 

 killing the animal and triturating the conjunctiva with a fatal dose of 

 abrin, an injection of the emulsion of the right or immunized conjunctiva 

 was without effect, whereas the emulsion from the left proved fatal. 

 Thus it will clearly be seen that the cells that had absorbed the abrin 

 had developed and contained antiabrin in sufficient amounts to neu- 

 tralize the poison. 



