CONFORMITY TO TYPE 247 



2. "In the place of simple dominance there may be manifest 

 in the intermediate hybrid offspring an intensification of character 

 or a condition intermediate between the two parents; or the 

 offspring may have peculiar character of their own (heterozygotes) . 



3. "A segregation of the characters united in the hybrid takes 

 place in their offspring so that a certain per cent, of these offspring 

 possess the dominant character alone, a certain per cent, the 

 recessive character alone, while a certain per cent, are again 

 hybrid in nature." 



When the attempt is made to follow a number of Men- 

 delian characters at the same time, the whole matter 

 becomes extremely complicated. 



When hybrids result from combinations of totally 

 different species they are usually infertile, have no 

 progeny, and so die without affording an opportunity 

 for the Mendelian law to be operative. 



It is sometimes difficult to prejudge what characters 

 may be subject to the Mendelian law. Thus whiteness 

 and color are Mendelian characters among most plants 

 and among the lower animals, but whiteness and black- 

 ness of the human skin are not Mendelian. On the 

 other hand, the color of the human eyes appears to be a 

 Mendelian character. Many spontaneously appearing 

 pathological conditions are Mendelian, as, for example, 

 polydactylism or excessive fingers and toes, hemophilia 

 or bleeder's disease, etc. The frequency with which 

 generations are skipped in the heredity of such condi- 

 tions is fully explained by the laws of dominance and 

 recession. 



One of the most recent theories of heredity, meriting 

 attention, is a chemico-physical theory which may be 

 described as the Lateral Chain Theory of Adami. 



In his "Principles of Pathology" Adami introduces 

 and explains the theory as follows: 



" We have already laid down that the primordial living matter 

 of the cell is contained in the nucleus; it is this matter that must be 

 carried over in the chromosomes. From this it follows that our 

 theory must be expressed in terms of biophoric molecules, and 

 that we have to endeavor to conceive a constitution of, and mode 

 of introduction between these biophores from the two parental 

 germ cells which will satisfy the various conditions. Coming 

 now to an analysis of the different forms of inheritance, we may 



