14- Heredity and Eiigeiucs 



Dc\'ries' jxuigene comj^lex are no better and perhaps no 

 worse than tlie h}-pothesis that racial memor_\' is the basis 

 of inheritanrc, or that the complex or harmonious eciui- 

 potential systems of Driesch "explain" the phenomena. 



As far as the facts of de\-eIopment and heredit_\- are 

 concerned, they might go on indehnitely repeating any 

 gi\'en series of events, but there would be only one t}'pe of 

 organism, alike at any and all points in the genetic chain. 

 Adequate e\'idence that there have been changes in this 

 series of events in the past and that changes are now going 

 on is found in the array of specific organic forms that exist 

 and have existed through geological history. How have 

 these changes been j)roduced ? 



The nineteenth-centur}' biology formulated its h^-pothe- 

 ses around two widely different concepts; an extreme 

 transmission liAi^othesis in which modifications arising in 

 peripheral parts — soma, i.e., personal peculiarities developed 

 in life — are transmitted to the progeny, through being in 

 some manner incorporated into the germinal constitution of 

 tlie race; and the hy]:>othesis that changes in the race arise 

 primarily in the germinal substance itself and appear later 

 in the soma. 



The idea of the peripheral origin of variations through 

 the stress of the conditions of life dates back to Buffon, 

 Erasmus Darwin, and Lamarck, whose ignorance of things 

 now common knowledge had led them to express the o])inion, 

 backed b}' much circumstantial evidence, that the condi- 

 tions of life, especially when changed, produced variations 

 which were heritable in the race. Darwin advanced the 

 h)'pothesis of an atomistic mechanism whereby this trans- 

 mission could concci\'abh' be produced and upon this pro- 

 visional hyi)othesis oi Pangenesis have been based all 



