1 7 8 LOCK : STUDIES IN PLANT BREEDING 



APPENDIX II.— EXPERIMENTS WITH CANAVA- 

 LIA ENSIFORMIS. 



This was the only strictly tropical plant with which satis- 

 factory crosses were obtained, but only a few were successful 

 out of many attempted. The plants possessed a very large 

 climbing habit, and it was consequently impossible to grow 

 many specimens, and when grown the individual plants were 

 difficult to disentangle. The first cross plants moreover failed 

 almost entirely owing to their having been sown out of the 

 proper season. 



The following points were determined : — 

 Tall habit dominant to semi -dwarf. 

 Pink colour in the flowers dominant (or nearly) to white, 



the latter reappearing in F 2 . 

 Absence of red pigment in the testa dominant to red. I □ 

 F 2 red reappeared, but in nothing like its former in- 

 tensity. Some of the plants of F 2 bore mottled grains, 

 but in these also the pigmented patches were of a very 

 faint reddish colour. 



In F 2 plants with no red pigment in the testa were more 

 numerous than (probably three times as numerous as) those 

 with reddish and those with mottled testas taken together. 



NO mottled strain was heard of as previously existing. 



The behaviour of the red character as described above is 

 remarkable, and possibly at present unique. It is unfortu- 

 nate that the difficulty already mentioned in combination with 

 want of time prevented further experiments. 



APPENDIX III.— RECENT PROGRESS IN THE 

 EXPERIMENTAL STUDY OF HEREDITY. 



Since the time of writing the account of the progress of Men- 

 delian studies, which appeared as Part I. of these studies, 

 steady have been made in the directions there indi- 



oated. 



