364 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



It is not possible to judge with absolute certainty concerning 

 every seed as to whether it is viable or not. Davis ('15) has 

 shown that such difficulty exists in Oenothera, in which large 

 numbers of seed-like structures may not germinate and that there 

 is great irregularity in the time of germination of viable seeds, 

 which makes it desirable to employ special methods in growing 

 pedigreed cultures. In sowing seed of Cichorium, it is my method 

 to sow the seeds from each head in separate seed pans containing 

 sterilized soil. The seeds are relatively few, thus far never more than 

 twenty-two for a pan. As soon as plants are well started they are 

 placed in pots and properly labeled, but the seed pan is kept for a 

 period of three or four months. Some irregular germinations have 

 been noted extending at the most over a period of about five weeks. 



There were no seed sowings from seed collections judged as 

 viable that did not give some germination. As far as tested no 

 plant was judged as self- fertile that did not produce some viable 

 seed. Not all seeds containing embryos proved to be viable. In 

 the plantings of 191 5, for example, selfed seeds of twenty-one 

 plants judged as self-fertile were sown to the number of 268; 

 from these 218 plants were grown into the rosette stage and there 

 were about 20 plants that died or were killed by slugs soon after 

 germination. On this basis the viability of seeds which were 

 judged as possessing embryos was about 85 per cent. 



RESULTS OF THE EXPERIMENTAL STUDIES 



Phenomena of self-compatibility and self-incompatibility 

 The experimental study of self-sterility in Cichorium Intyhus 

 was begun by the writer in 1912, when it was found that numerous 

 plants of both wild and cultivated strains failed to set seed when 

 self-pollinated under control. The investigations were originally 

 planned to test the inheritance of flower color and other char- 

 acters in wild white-flowered plants by inbreeding, and by crossing 

 with blue-flowered plants of both wild and cultivated stock. In 

 1 91 1, seeds were collected from three wild white-flowered plants 

 that were growing on the campus of the University of Wisconsin. 

 Later these plants, designated as yl, B, and C, were dug up and 

 replanted in the breeding plots at the New York Botanical Garden. 

 The seed collected from these plants was sown in October, 191 1; 



