18 
Transactions Texas Academy of Science. — 1907. 
(Fig. 3.) In either case, the toxin wonld be powerless to combine with 
the protoplasm. 
Also it is easy to understand how immunity can be acquired rapidly 
by the introduction of antitoxin. For the antitoxic serum supplies the 
blood of the patient with receptors that its own blood does not yet 
possess, and the toxin molecules combine with these receptors. 
