PLANT BREEDING 



353 



Fig. 9. Recombination of characters of Plants shown in Fig. 7, occurring 

 in the second hybrid generation. This is a uniform and constant type having the 

 short habit of growth and large leaves of the " Havana " parent, combined with the 

 high number of leaves of the " Cuban *' parent. It is now grown in the Connecticut 

 River valley and yields 40 per cent, more than the Havana type. 



treme segregation. To take a hypothetical case, suppose two plants are 

 crossed in which the flowers of one are twice as long as the flowers of 

 the other and that this extra length is controlled by three or four sepa- 

 rately heritable factors. If only a few of the egg cells can be fertilized 

 on account of dissimilarity from the pollen cells, one would expect only 

 those seeds to be formed that would come from the fusion of the germ 

 cells nearest alike. Intermediates would therefore be more likely to be 

 formed than extremes. There is one other possible way of accounting 



