F. C. Miles 197 



green plants and heterozygous green plants the two classes could not 

 be distinguished by any visible character. Progenies of heterozygous 

 plants consisted of three green plants to one white one. 



In rye he noted the pure white-leaved type of plant, and also a 

 distinct yellow-leaved type, which in inheritance is analogous to the 

 white type. The plantlets of both types are incapable of surviving the 

 seedling stage. Green is dominant in both cases, and there is no "aurea" 

 type such as that described by Baur in Antij-rhinum, and also in Pelar- 

 gonium. He believes that the white condition of the leaves is due to 

 the omission or suppression of some factor, and that the yellowish con- 

 dition is due to the suppression or omission of a second factor. 



He reported having found white plants among his cultures of oats, 

 but no record of the behaviour of the character was given. 



The Inheritance of Albinism in Maize. 



The experimental work which is hei-e reported was conducted at the 

 Nebraska Agricultural Experiment Station under the direction and 

 supervision of Dr R. A. Emerson, who had begun investigations on these 

 problems, and who kindly placed at the writer's disposal the records of 

 the work so far as it had progressed, together with the seed for con- 

 tinuing it. The writer takes this opportunity to express his appreciation 

 of the gi-acious assistance and many valuable suggestions which Doctor 

 Emerson has given him. The colour drawings reproduced here were 

 made by Miss Carrie M. Preston of the Nebraska 'Agricultural Experi- 

 ment Station, to whom the writer desires to express his thanks for this 

 assistance. 



Since Emerson (10) has shown conclusively the recessive nature of 

 the pure white plants (PI. VIII, fig. 1), little attention has been given to 

 the inheritance of this case of albinism other than to count the white 

 and the green plants in each progeny where both types have occurred. 

 In the fourteen families that have been grown since the spring of 1912 

 there was a total of 361 green plants and 130 white ones, which approxi- 

 mates very closely the theoretical ratio of three green plants to one 

 white one. 



More attention has been given to the case of the yellowish-white 

 individuals (PL VIII, figs. 3, 4 a, 4 h, 5 and 6). In the twelve pro- 

 genies which threw both green plants and yellowish-white ones there 

 were 726 green plants, 260 yellowish-white ones, and 5 which were 

 striped. It was possible to self-pollinate two of the striped plants, but 



