304 THE FOUR INSEPARABLE FACTORS OF EVOLUTION. 



4. Initiation and Genesis in Heredity. 



We must again (see p. 291) make clear the comprehensive nature of heredity 

 in relation to our law of the four inseparable factors. As one of the four factors 

 heredity includes the forces underlying all that is heritable, whether resemblance 

 or variation, whether patent or latent, dominant or recessive, ancestral or new; 

 forces which are inseparable from those of environment and ontogeny. Thus the 

 term is employed in a more comprehensive sense than by some other recent 

 authors. For example, Castle in his work Heredity in Relation to Evolution and 

 Animal Breeding (1911) attaches the following meaning to heredity: "By 

 heredity, then, we mean organic resemblance based on descent.' ' Another 

 author, Jennings, observes: "An organism's heredity is its method of responding 

 to the environmental conditions." 



Far closer analysis as regards the problems of initiation and genesis is de- 

 manded in heredity than in ontogeny. In the biology of the past there were a 

 number of loosely accepted principles which the modern exact study of genetics 

 is compelling us to examine far more closely; this demand for rigid analysis is 

 one of the greatest services rendered by the recent students of genetics, inspired 



by Mendel. 



There are five great classes of problems awaiting solution in heredity: 



1. What are the relations between initiation in environment and ontogeny 

 and the genesis of new characters in heredity? 



2. Is there any real genesis of new characters in heredity without initiation 



by environment or ontogeny? 



3. Does the genesis of new characters in heredity conform or show a likeness to 

 the antecedent initiation of environment or of ontogeny, or is it independent of it? 



4. Is genesis in heredity exclusively a continuous 1 or discontinuous process, 

 or do we observe both modes of continuity and discontinuity? 



5. Is genesis in heredity a process ordered by law or is law established indirectly 

 through elimination of the lawless (inadaptive) and selection of the lawful 

 (adaptive) out of an indefinite number of trials? 



It is not the purpose of this contribution to attempt to discuss any of these 

 five classes of problems or to review the various answers which are being given 

 by investigators in different fields at the present time. 



The kinds of characters which require analysis as regards initiation and 



genesis have been fully enumerated in a preceding section, p. 300. 



5. Genesis as Observed in Paleontology. 



The author's opinions, which are based on prolonged palseontological obser 



vations but which await verification, are the following 



.2 



1 Osborn, H. F.: The Continuous Origin of Certain Unit Characters as Observed by a Pale- 



ontologist, Harvey Lecture, Amer. Naturalist, vol. XL VI, No. 544, Apr., 1912, pp. 185-206 

 May, 1912, pp. 249-278 



9 



Osborn 



Amer 



Amer 



