172 Genetic Behaviour of the Hyhrid Primula Kewensis 



difficult to analyse. No plant like if appeared. These results are in 

 accordance with those obtained from Jlorihunda x if, to wiiich we shall 

 now pass. 



P. jlorihunda x if. 



We obtained five families from this cross. In four of these crosses 

 the florihunda mothers used were from the cross floribunda x verti- 

 cillata, and in the fifth cross a pure-bred floribunda was used. There 

 was a general resemblance between the offspring of all these crosses. 



The F^ plants showed great variation, but all of them would be 

 classed as floribanda-\\]s.& plants. Characters which they all possess, 

 and which are common to floribunda, are the small size, dimorphic 

 flowers, hairiness, and absence of meal. In F.^ and F^ the same general 

 features were exhibited. The lai-ge size, the mealy character and the 

 scented flowers of |!i, which may be supposed to come from verticillata, 

 never reappeared in these families. The difficulty of classifying all the 

 degrees of variation which occur for every character makes it impossible 

 for us to do more than make a general statement. Evidently a very 

 large number of factors are involved, and except in the case of colour 

 we shall not attempt to give precise figures. 



In size, habit, leaf and flower shape, and degree of hairiness, very 

 great variation occurs. The smaller plants do not always breed true, 

 even when derived fi'om the larger. The habit may be flexuous or 

 bending as in floribunda, or erect as in verticillata, but thei'e is a wide 

 range of intermediates, many of which are erect in the early stages of 

 growth and flexuous later. At the time of flowering the plants may 

 still be single-crowned rosettes, or they may have broken up into many- 

 cro\vned tufts. The former plants have hitherto bred true to this 

 character. The time of flowering and the length of the flowering 

 period vary greatly, and there are numerous morphological differences 

 connected with these characters. The leaves vary from long narrow 

 ovate as in verticillata to broadlj' ovate, and may be pointed, rounded, 

 or obovate at the tips. The length of the petiole varies also. The 

 petals are stellate or imbricate, flat or reflexed or funnel shaped ; 

 the corolla tubes vary in length. The hairs range from very short 

 glandular hairs approaching the Keivensis type of hair to long pointed 

 hairs Uke those of floribunda. 



Sterility. 



The male sterility of |f reappears in many of the families from 

 floribunda x i|. In these families the anthers may contain very little 



