LUTHER BURBANK 



spring will be susceptible. But it means also that 

 the recessive quality of immunity will reappear 

 in one fourth of the offspring of the second 

 generation. 



And thereby hangs the tale of Professor Biff en's 

 great achievement, as will appear in a moment. 

 Characters That Do Not "Mendelize" 



Before following this let us glance at the other 

 groups of unit characters which Professor Biffen 

 found not subject clearly to the rules of dominance 

 and recessiveness. 



These groups include fewer characters than 

 those in the dominant list, partly perhaps because 

 it is obviously more difficult to study characters 

 that do not show the clear phenomena of dom- 

 inance and recessiveness. But these groups are 

 highly interesting none the less. The unit char- 

 acters that showed what Professor Biffen speaks 

 of as irregular dominance as studied in this inves- 

 tigation, were only two, namely: (1) felted glumes 

 versus glabrous glumes; and (2) gray colored 

 glumes versus red or white glumes. 



The glume, perhaps it should be explained, is 

 a bract that has no particular interest for anyone 

 except the botanist, but which may serve admir- 

 ably in checking the results of experimental breed- 

 ing. The glumes have practical significance for 

 the agriculturist, because their character deter- 



[62] 



