156 THE ROYAL SOCIETY OF CANADA 



proved partially sterile that the records would not have been suffici- 

 ently comprehensive to justify the labour. Many small families were 

 raised, however, and general observations made on them. The re- 

 sults appeared to be very similar to those already described. Some 

 families appeared to be as early as the early parent, and some as late 

 as the late parent, but most were quite obviously intermediate with 

 various degrees of earliness. For theoretical purposes, therefore, it 

 seems safe to extend the conclusions to this cross. 



The results of another cross involving very different parents 

 (B and E) are given in Table V. The difference between the parents 

 this year was not nearly so great as is usually the case. The simi- 

 larity to Tables III and IV is obvious. In this case there seems to 

 be little doubt that some of the earlier families of the third generation 

 are genetically earlier than the early parent. It may be mentioned 

 that from a cross between this same variety E and another variety 

 which ripens at about the same time, families were raised which 

 ripened much earlier than either parent. Detailed records, however, 

 are not available. It appears that the variety E, even though very 

 late itself, makes a contribution for earliness which is lacking in the 

 other varieties. In the cross B x E, no families later than the late 

 parent were found, but whether this is due to the small number of 

 late F2 plants chosen cannot be definitely stated. 



For economic reasons a larger number of families of the cross 

 A X C than of any other were grown and studied. But as the re- 

 sults are very similar to those already described and as the cross in- 

 volves neither very small nor very wide parental difference, the data 

 are not given in extended form but are condensed in table VI. The 

 position of most of the families on the left of the table is due partly to 

 environmental influences, partly to the method of recording them by 

 their earliest plants, and partly to the fact that the great majority of 

 the plants chosen are, for economic reasons, within the range of the 

 early parent or intermediate (see columns 2 and 3). It is possible 

 that some of the families are genetically earlier than the early parent 

 but this cannot be stated positively from the results of one year's work. 



I also have records on several other crosses between parents at 

 different places on the whole scale of variation. In one case the differ- 

 ence between the parental means is as small as three days. But as 

 the results are very similar to those just described, it has not been 

 thought necessary to include them. The results for all the crosses are 

 remarkably uniform, including families whose ranges of variation 

 occupies various portions of the whole range of parental variation and 

 occasional families extending a little beyond one extreme or the other. 



