3 2 4 PLANT-BREEDING 



some characters of the flower are affected, and in the second 

 place, some of the leaves. In the flowers, the stigma is broad- 

 ened and flattened and less regularly divided into its four parts. 

 The ovary, which is inferior in the normal species, is her^ 

 only partially so, and its cavities are seen to protrude above 

 the insertion of the calyx tube, occupying thereby the basal 

 part of the style. How these changes may be brought about 

 by the same cause that shortens the style, we do not under- 

 stand. But far less can we guess the connection between 

 the marks of the flowers and the foliage. The leaves of the 

 brevistylis have more rounded tips and the plants may, by 

 this means, be recognized weeks before the development of 

 the flower buds, and sometimes even in the rosette stage. 

 This instance of correlation seems analogous to the facts 

 observed among cereals and other cultivated plants. We 

 can only acknowledge the fact from the regularity of the 

 occurrence of the combination, without even being able 

 to guess its cause. 



Of course, there art also correlations which we may 

 understand or at least believe we understand. In our case, 

 one of these is seen in the broader flower-buds of the CE. brev- 

 istylis, when compared with the CE. Lamarckiana. In the 

 latter the calyx is extended by the growth of the style, which 

 presses the stigma from within against its tip. The calyx 

 being thereby elongated, it is only natural that its form be- 

 comes more conical as soon as the long style is absent. Per- 

 haps another mark may be explained in a similar way. At 

 the time of the ripening of the seeds the (E. brevistylis is 

 easily recognized by its very small pods, containing hardly 

 any seed. It may be assumed, although a direct proof is 

 wanting, that the elongation and narrowing of the ovarial 

 cavities within the base of the style is an impediment to the 

 growth of the pollen- tubes, and thus hinders a- normal fertil- 

 ization. 



