loS Heredity and Eugenics 



in the hybrid it matters not whether they are dominant 

 or recessi\'e or whether there is no dominance, there will 

 be no dilution from intercrossing. A second and more 

 important advantage, due to the operation of the law, 

 results from the recombination of characters. Characters 

 may be transmitted as units and chance recombinations 

 of these characters may occur without anything really new 

 to the organism being formed, yet in this recombination 

 the organism as a whole may be better fitted for its environ- 

 ment than ever before. And this is giving recombination 

 its smallest value, for, however independently potential 

 characters may be transmitted, no one believes that a 

 developing organism is simply a mass of independently 

 developing unit-characters. The characters of an organ- 

 ism are more or less dependent upon one another in their 

 expression, and in this interdependent development the 

 greatest possibility for good recombinations occurs. Theo- 

 retically nothing new may result from the mere act of cross- 

 ing, but practically a new combination of old characters 

 ma>' result in something c^uite different. A little thought 

 and the use of chemical analogies where the same mixtures 

 produce different chemical results under different physical 

 conditions, show the importance of this conception to Men- 

 delian theory. Yet it is not necessary to believe the cur- 

 rent teaching that one has only new recombinations and 

 not new characters to deal with in crosses. The theory 

 that several germ-cell factors may be due to produce the 

 same character gives us a reasonable and orthodox explana- 

 tion of the origin of characters really and truly new by the 

 interaction of gametic factors that are old. For example, 

 let us suppose that in a certain species with a petioled leaf 

 there is a \ariety which has the presence of factor A pro- 



