No. 524] CHROMOSOMES AND HEREDITY 



451 



must be admitted at the outset that the distinction be- 

 tween the two is largely theoretical and possibly temper- 

 amental. To some minds it appears that to admit that 

 every detail of character is represented by the egg must 

 mean that something material in the sense of some actual 

 particle that stands for each detail must be present. To 

 other minds it seems only necessary to admit that eggs 

 are made of different materials in order that the outcome 

 of the development may be different, and that these dif- 

 ferences between eggs, while leading to differences in the 

 end product, need not be conceived as different material 

 particles in the sense that the particles become the ulti- 

 mate characters that differ. 



Both views postulate an initial difference in the egg, 

 but one view conceives the differences in the egg to be 

 associated with particles that are in some way directly 

 responsible for the different characters, while the other 

 view conceives adult characters to be the product of an 

 elaborate series of processes and that the material dif- 

 ferences in different eggs are too remotely connected 

 with the end product of their development for us to 

 think of those differences in terms of special or separate 



ever view we adopt will depend' first upon which concep- 

 tion seems more likely to open up further lines of profit- 

 able investigation, and second which conception seems 

 better in accord with the body of evidence at hand con- 

 cerning the process of development. 



It may be said in general that the particulate theory is 

 the more picturesque or artistic conception of the de- 

 velopmental process. As a theory it has in the past 

 dealt largely in symbolism and is inclined to make hard 

 and fast distinctions. It seems to better satisfy a class 



though the solution l.o purely formal. But the very in- 

 tellectual security that follows in the train of such the- 

 ories seems to me less stimulating for further research 

 than does the restlessness of spirit that is associated 

 with the alternative conception. The purely adventur- 



