272 University of California Publications in Agricultural Sciences [Vol. 2 



in culture 21.99. Tn 1922 a culture of six chlorina plants was obtained. 

 When those elilorina plants were crossed with normal pfreen plants, 

 the tAvo classes of plants — normal and chlorina — appeared in the 

 progeny in e(pial numbers, thus indicatini? Iliat the chlorina plants 

 were heterozygous for green. Self-fertilization of the green resulted 

 in only green progeny. The seedling progeny from self-fertilized 

 chlorina plants consisted of tliree classes: pure yellow, pale green, and 

 normal green, in the ratio 1 to 2 1o 1. The yellow seedlings died, the 

 pale green ones developed into chlorina plants, and the green seed- 

 lings produced only green plants. The gene for chlorina is therefore 

 dominant and has a lethal action when homozygous. 



TABLE 14 

 Segregation op Seedling Progeny of Self-fertilized Chlorina Plants 



In table 14 the seedlings in culture 24.174 intergraded in such a 

 way that it was impossible to make an accurate segregation of pale 

 green from green ; consequently the two classes are combined in the 

 table. Separation of the two green types in other cultures was less 

 difficult, although it is apparent that some pale green plants have been 

 included in the green class. 



GOLDEN YELLOW (y) 



The tjTpe known as golden yellow behaves as a monohybrid reces- 

 sive as shown by data in table 15, 



These golden yellow seedlings gradually develop chlorophyll and 

 finally reach maturity, although growing much more slowdy than 

 their green sibs. These plants can, however, be distinguished in the 

 mature stage, due both to size and to the peculiar distribution of the 

 chlorophyll. Thej^ produce mature rosettes that show a mottling 



