262 



BIOLOGY: GENERAL AND MEDICAL 



When the ovum thus matured is fertilized by one of the sperma- 

 tozoa thus evolved, the result is an organism whose somatic and 

 germinal cells must all have a chromosome combination diagram - 

 matically represented thus 



Fi = lst filial generation (Hybrid). 



Taking male and female organisms with germ plasm of this com- 

 bination, it follows that in the reduction or heterotype division of the 

 oocyte and spermatocyte, a separation of these chromosomes will be 

 effected. 



Four oocytes are intro- 

 duced because there will 



be four 8 P ermatozoa - 



In the homotype mitosis these arrangements 

 will not be changed, and the results will be 



F2=2d filial generation, resulting from the fertilization of the ova of hybrids 

 by the spermatozoa of hybrids. The following possibilities are shown: 



Pure wh'ite^ 



(?) Pure black 



Mendelian proportions. 

 Fia. 104. 



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 



