SIDE CHAIN THEORY OF EHRLICH. 



(i.) The invading haptophore may so 

 closely resemble the normal haptophore as to 

 perform the function of the latter, and so no 

 harm is done. 



(2.) It may combine with neither good nor 

 bad result, but may deprive the cell of its nutri- 

 tion by reason of its having displaced the 

 normal haptophore. 



(3.) It may be directly or indirectly inju- 

 rious or destructive by means of an associated „ 



■^ Toxophorus 



toxophorous (poisonous) group. It will thus be Groups, 

 understood that toxins are conceived to be com- * 



plex, composed of fixation or binding groups 

 (haptophores) and poisonous groups (toxo- Qinsups. °'"^ 

 phores). The cells of the body Ehrlich believes 

 to possess and to furnish appropriate receptor 

 groups, haptophiles and toxophiles, through 

 which the respective combinations are effected. 

 But until the haptophore of the toxin has been 

 taken up by the haptophile of the cell, the toxo- 

 phore cannot attack the toxophile. He also 

 believes a bacterium to be a chemical compound 

 made up of two or more chemical groups, close- 

 ly or loosely combined. When a bacterium Chemical _ 

 ■' •' • 1 .u Composition 



enters the body and comes m contact with the of Bacteria. 



lateral or "side-chain". groups of the body cell, 

 the receptor (antitoxic), group combines 

 chemically with the toxic group of the invad- 

 ing bacterium. If the chemical affinity between 

 the toxic group and the receptor (antitoxic), 

 i6s 



