INTRODUCTION 15 



stimulated ; they may assume increased growth and at the same time undergo 

 cerain structural and metabolic alterations. These characteristics may be main- 

 tained permanently and when this has occurred, then normal tissues have been 

 changed into cancerous tissues. It can be shown that the latter still possess 

 essentially the organismal differentials of the host from which they are de- 

 rived ; but they differ from the latter by an increase in the growth momentum 

 which enables them in certain cases to overcome, in a new host, injurious con- 

 ditions to which normal tissues would succumb ; they also seem to possess a 

 greater ability to adapt themselves to strange hosts and, moreover, they give 

 off more efficient antigens than do normal tissues. 



It is essential for the completeness or fulfillment of the individuality in 

 higher organisms that the integrity of the individuality differentials be main- 

 tained. An intrusion of strange substances not bearing the same individuality 

 differential sets in motion reactions which lead to their splitting, their destruc- 

 tion, or their elimination, in some instances after they have been made innocu- 

 ous through conjugation with other substances. The primary local tissue reac- 

 tions, as well as the secondary local reactions of allergy and the general reac- 

 tions of immunity, serve this purpose. But the organism must also build up 

 his species and individuality differentials out of non-specific material or out 

 of material which carries unsuitable organismal differentials ; the processes of 

 splitting by means of digestion and those of syntheses lead to the production 

 of building stones endowed with the right type of specificity, and they bring 

 about the replacement of lost tissue and the addition of new material. The 

 specificity of enzymes plays an important part in these operations. There are 

 thus strong indications that the individuality differential has these functions : 

 (1) to co-ordinate and to equilibrate the mutual interaction of adjoining and 

 also of some distant tissues in such a way that the inner integrity of the in- 

 dividual is insured, and (2) to combat admixtures from strange organisms 

 and perhaps also to react against foreign bodies which are devoid of organis- 

 mal differentials. 



The organism is, then, a harmonious whole, a combination of the mosaic 

 and of the essential type of individuality; in it, therefore, not only the organ 

 functions are adapted to one another, but also all the various tissues, though 

 apparently functionally unrelated, are specifically adapted to one another, 

 owing to the nature of their organismal differentials. This latter adaptation is, 

 above all, what characterises the individual. Such a harmonious relationship 

 must be based on resemblances or identities in certain chemical structures of 

 the most important and complex substances which enter into the building of 

 the organism, especially substances of a protein nature. Accordingly, it has 

 been established that the hemoglobins and hemocyanins, derived from various 

 species, or from still larger groups of animals, are the most nearly identical in 

 structure in the nearest related animals and are the more dissimilar in struc- 

 ture the farther distant the species are. In accordance with what we have 

 already stated, we may assume that the same chemical gradation in the struc- 

 ture of the organism in correspondence with phylogenetic relationship must 

 go still further, not only each species but each individual possessing its 



