1913] Charles Frederick Bolduan 255 



Ehrlich makes use of an hypothesis advanced by Weigert in con- 

 nection with regeneration. According to this, physiological func- 

 tion and structure depend upon an equilibrium of the tissues that is 

 maintained by virtue of mutual restraint between their component 

 cells. Destruction of a single integer or group of integers of a 

 tissue or a cell removes a corresponding amount of restraint at the 

 point injured, and therefore destroys equilibrium. This permits 

 of the abnormal exhibition of bioplastic energies on the part of the 

 remaining uninjured components, which activity may be viewed as a 

 compensating hyperplasia. When such bioplastic activity is called 

 into play there is always hypercompensation ; that is, there is always 

 more plastic material generated than is necessary to compensate for 

 the loss. Thus far Weigert. 



Ehrlich, in line with Weigert's over production theory, points 

 out that, owing to the combination of toxin with receptors of the 

 cell, the receptors are practically lost (at least temporarily) to the 

 cell; that the cell or its fellows now produces new receptors to re- 

 place this loss ; but that this production always goes so far as to make 

 a surplus of receptors ; that these receptors are thrown off by the cell, 

 as unnecessary bailast so to speak, and then circulate in the blood as 

 antitoxin. The same substance therefore, which, when part of the 

 cell, combines with the anchoring group of the toxin, enabling this 

 to act on the cell, when circulating free in the blood combines with 

 and satisfies this anchoring group of the toxin, and prevents the 

 poison from combining with and damaging the cells of the organism. 

 It is obvious that this affords a complete explanation of specificity. 



If we now go back to our diagrams (plate 2) we shall see that 

 all of the antibodies discussed above fit readily into this scheme. So 

 far as the antitoxins are concerned, these would be merely receptors 

 of the first order, thrust off from the cell and circulating in the 

 serum. Agglutinins and precipitins would belong to the second 

 Order; they have the active group as an integral part of the receptor. 

 The hemolysins and bacteriolysins would be in the third order; 

 fresh serum is active because it contains complement, but since 

 the complement is very labile, the serum after a while contains only 

 the immune body, i. e., that part of the receptor which anchors the 

 food molecule on the one band and the ferment substance on the 

 other. 



