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1920] COULTER— HEREDITY 461 



The by -products which originally accumulated in the protoplast 

 were of various types. Some were very toxic, and these, if they 

 were not immediately eliminated, resulted in the death of the 

 organism. Others were less toxic, relatively more harmonious with 

 the protoplast itself. These last, since they were not immediately 

 fatal, stimulated an adaptive response on the part of the protoplast. 



As to the general nature of this adaptive response, an important 

 assumption must be made. Recent researches upon mammals 

 have revealed in these organisms the power to develop antitoxins. 

 The presence of a small quantity of toxin stimulates the organism 

 to an adaptive response, the development of an antitoxin specific 

 for the toxin present. This power is probably one of the funda- 

 mental characteristics of all protoplasm, being present even in the 



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most primitive organisms. 



Certain by-products in the primitive organism, only slightly 

 toxic in their effect, stimulated it to produce an antibody. The 

 protoplast is doubtless a colloidal system, and we may consider 

 antibodies in the following light. The antibody counteracted 

 the influence of the toxic by-product by insulating it from contact 

 with the protoplast. Antibodies were probably developed most 

 successfully for those by-products which were the least toxic in 

 their effect. These by-products then became insulated by the 



* 



antibodies. This insulation was significant not only in cutting 

 off the influence of the by-product upon the protoplast, but in 

 another respect also. At cell division this by-product, even though 

 exposed, is not oxidized because of the protection afforded by the 

 antibody which insulates it. It is probably this mechanism, for 



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the most part, which accounts for the fact that some of the by- 

 products are passed on to the daughter protoplasts, as mentioned 

 before. These by-products are the primitive bearers of hereditary 

 characters. The program carried out by the primitive hereditary 



mechanism is as follows. 



The life of the primitive organism, like that of all organisms, 

 involves a series of reactions. Early in the life of the organism 

 there is present a certain reaction system, characterized by certain 

 physical and chemical conditions. For a time the reaction system 



