258 BIOLOGY OF SPECIALIZED GROUPS 



haps, more closely related to the soluble toxins. They can, 

 for all practical purposes, be regarded as modified toxins 

 which have a special affinity for red blood corpuscles. These 

 hemolysins are divided into distinct chemical molecules, a 

 complement or thermolabile substance, and an amboceptor or 

 thermostable substance, as have been noted in the bactericidal 

 substances in the serum. 



Hemolysins are contained in the secretions or extracts of 

 animal and plant cells, such as snake venom, eel serums, and 

 the various phy to toxins above mentioned. The mechanism 

 of hemolysis (blood destruction) is very similar to bacteriolysis 

 (bacterial distraction). 



Antitoxins. Practically all cells of the body possess 

 physiological receptors (side chains), composed of definite 

 chemical radicals connected with a central group of atoms or 

 molecules. These side chains have open valencies and are 

 capable of uniting with various foreign substances, such as 

 food, poisons, etc. The classical example used to demonstrate 

 a central group and its side chains is the benzene ring and 

 the substances which may be formed from it : 



H COOH COONa 



I I I 



c c c 



H C C H H C C H H C C H 



