1920] 



Collins: Inbreeding and Crossbreeding in Crepis Capillaris 



209 



to the inbred cultures. Seed secured from wild plants in Berkeley, 

 California, was used in 1916 to start the culture 17.192. Cambridge 

 (Quy Fen), England, is the source of culture Z9. The latter were 

 slightly more vigorous than the Berkeley plants. Culture 17.178 was 

 grown from seeds from wild plants found growing near Eureka, 

 Humboldt County, California. 



Culture e33, which was used as one of the parents of crossbred 

 culture 129, is a reciprocal of e32, and similar in all respects. 



Pedigrees of the plants used in these experiments are shown in the 

 accompanying tables. In Table 1 two systems of symbols are used to 

 designate cultures. In the parent stock and in the first and fourth 

 generations the annual-notebook-page-number system of Shull is used. 

 In the second and third generations individual cultures are designated 

 by key letters combined with numbers. In both tables individual 

 plant numbers are designated by P with a subscript. In Table 2 the 

 same systems are used together with special key letters (H and Z) to 

 designate certain cultures. 



Table 1 — Shoaving Pedigrees of Plants Used in the Inbreeding Experiment 



Table 2 — Pedigrees op Crossbred Plants 



