288 



Are now both of these theories compatible with one 

 definition of ''determined"? Are they both possible and 

 both necessary? 



Loeb has stated the problem and the ''compromise" in 

 these words (1916, p. 245): 



(^nkhn's concUisions are (1915, p. 170) : 

 There is no doubt tliat most of I he differentiations of the e£?<r cyto- 



of the interaction of nucleus and ovtoplasni: hut the fact remains that 

 at the time of ftrtili/'ition the lineditn% pohncu^ of tlu \^^o ^nm 



tion of future organs, beuio: foreshadowed m the cytoplasm of the egg 

 cell while onlv the differentiations of later development are influenced 

 hv tlie s()erni. In short the egg cytoplasm fixes the general type ot 

 development and the sperm and egg nuclei supply onlv the details. We 

 are vertebrates because our mothers were vertebrates and produced 

 eggs of the vertebrate pattern — but the color of our skin, eyes and hair 

 . . . were deteiTnined by the sperm as well as by the egg from which 



The ^;unc antli..!- lia^ rritrrafd ;,n,l M.iiirwliat elaborated 

 the saiii.- vicw> ill an iiMpiil.li^h..l imixT piv^MitiMl before 

 the X;i!'m!>;iI A.-nhMiix nf S,-i, n.-r in Xoveinb. |-, liHfJ.i 



i s: - ;>apor (1917) has been published. 



In ::itt'rially the view which he had 



pri'i X rted equally by the egg and the 



gperii! ' ; ; _ r . : i > . tlie view mainfeined by the present 



