Further Studies on the Apogaray and Hybridization of the Hieracia. 2^)0 



a. The 7'h of July 1906 I pollinated an isolated head of H. auricula 

 (the same set which was used for castration experiment; No. M 17) 

 with pollen from an isolated head of H. auraiitiacum (this too had been 

 used — and with positive result — for castration experiment; No. 58). 

 Only four specimens appeared from the sowing of the seeds gathered, 

 and these were all hybrids, all unlike each other, standing in their 

 characteristics in different degrees between the parents. No correlation 

 seems to exist between the different characters; e. g. a hybrid, in 

 colour of the flowers near to H, aurantiacum, does not also in other 

 characters resemble the father. 



With regard to the colour character the family showed the follo- 

 wing gradation: 



I specimen (No. 2861) was very near to H. aurantiacnin. 



I specimen (No. 2863) was less near than the preceding, but still 

 nearer to the father than to the mother. 



I specimen (No. 2860) was intermediate or perhaps a little nearer 

 to the mother. 



I specimen (No. 2864) died before I had noticed its flower colour; 

 it was a decided hybrid. 



The first two specimens do not seem to be able to have full 

 fruit; at least, it appears from castration and isolation experiments, 

 that they are self-sterile. The third one (No. 2863), however, has 

 yielded fruit after castration. Already under the first scanty flowering 

 in autumn 1907 one head was castrated. The small number of fruits 

 gathered from this experiment were sown in May 1908, and the 

 plants (Fo) reached a scanty flowering in September of the same year 

 and have later flowered copiously in 1909 (June). Again the family 

 F2 consists of only four specimens, but these are all quite alike in aU 

 characters and quite similar to the parent plant; they have given a fair 

 number of fruits. Castration of Fj (No. 2863) was repeated in 1908 

 and out of the much more numerous offspring (No. 467) one plant reached 

 flowering in September 1909; it was also quite similar to the parent 

 plant, and the same seems to be the case with the remaining ones, 

 as far as can be judged from the vegetative characters alone. 



We are thus allowed to conclude, that while the first gene- 

 ration (Fj) of //. «rar/cw/rtx d:?<ra«//rtt?/w2 is heterogeneous, the 

 second generation (F2) is quite homogeneous and like the 

 parent individual of F] , in so far as it can arise at all. 



b. As the experiment reported on only gave a few hybrid specimens, 

 the same cross, with the same parent individuals, was repeated in 1907. 



