Chapter 8 

 Toxins and Organismal Differentials 



The organismal differentials are recognized by means of certain 

 definite reactions which are called forth when a strange differential 

 is introduced into an organism. The reaction may be a primary one, 

 or it may be a secondary immune reaction. These effects may follow trans- 

 plantation of pieces of tissues, as well as injections of bodyfluids or of ex- 

 tracts of tissues from other organisms, and they cause a disequilibrium of 

 the host to a degree which varies with the relative strangeness of the 

 organismal differentials of donor and host; the intensity of the reaction of 

 the host tissues against a strange graft or material injected is to a large extent 

 a measure of this disequilibrium and of the degree of strangeness between 

 host and transplant, although some accessory factors may modify the 

 intensity of this reaction within certain limits. We have found throughout 

 that the farther distant the relationship between transplant and host, the 

 greater the incompatability which results from transplantation. This applies 

 to transplantation in higher, more differentiated organisms as well as in 

 embryos of amphibia; but as a rule, it is only the transplant which suffers, 

 the host being in such a favorable position that no serious injury is inflicted 

 upon it in the large majority of cases. However, we have referred to some 

 instances in which the transplant exerted a toxic effect on the host, as, for 

 instance, in the transplantation experiments of Diirken and Kusche, and in 

 the transplantation of amphibian eggs in the experiments of Weber and others. 

 There were indications that in some of these transplantations we had to deal 

 with the injurious effects of special substances rather than with the specific 

 action of distant organismal differentials. 



If these special substances orginate in an organism and normally come 

 in contact with its various tissues acting as endorgans, and especially if they are 

 present under ordinary circumstances in the circulating bodyfluids, they are 

 as a rule not toxic for this organism. There is a mutual adaptation between 

 the cells and organs and these autogenous substances. But under abnormal 

 conditions such constituents of the body may be carried to tissues with which 

 normally they do not come in contact, and then they may act as poisons ; thus 

 bile in contact with the pancreas or other tissues of the peritoneal cavity may 

 be toxic, or if complex substances constituting the body, such as certain pro- 

 teins, are split in an abnormal manner and these split products come in 

 contact with organs and tissues of the organism, they may have injurious 

 effects. Also, if hormones which are not toxins in the ordinary meaning of 

 this term, are formed in excess, as may occur following an increase in the 

 amount of tissue producing the hormones or following a more intensive stimu- 

 lation of this tissue, or if the hormones are deficient in quantity, due to a lack 

 of the necessary tissue in which they originate or to a lowering of its metabo- 



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