346 TEE AMERICAN NATURALIST [Vol.LVI 



chromosomes so far examined showed 10 bivalents and 

 2 trivalents at the first prophase. 



Thus the random assortment of chromosomes in trip- 

 loid Daturas parallels the conclusions as to the random 

 assortment of genes in triploid (trisomic) inheritance, 

 and adds to the evidence for the chromosomal theory of 

 heredity given by the cytological and genetic work on 

 Drosophila (4) and other insects. 



LITERATURE CITED 

 1. Belling, J. 1921. The Behavior of Homologous Chromosomes in a Trip- 

 loid Canna. Proc. Nat. Acad, of Science, 7: 197-201. 

 Blakeslee, A. F. 1921. Types of Mutations and their Possible Signifi- 

 cance in Evolution. Amks. Nat., 55 : 254-267. 

 Blakeslee, A. F., J. Belling, and M. E. Farnham. 1920. Chromosomal 

 Duplication and Mendelian Phenomena in Datura Mutants. Science, 

 52: 388-390. 



Bridges, C. B. 1921. Triploid Intersexes in Drosophila melanog aster. 



Science, 44: 252-254. 

 Gates, R. R. 1909. The Behavior of Chromosomes in CEnothera lata X 



Geerts, J. M. 1911. Cytologische Untersuehungen einiger Bastarde von 

 (Enothera gigas. Ber. d. Deutsch. Bot. Ges., 29 : 160-166. 



de Mol, W. E. 1921. Over het voorkomen van heteroploide varieteLten 

 van Hyadnthus orientalis L. in de Hollandshe kulturen. GenetiTca, 3 : 

 97-192. 



Osawa, I. 1920. Cytological and Experimental Studies iji Moms, with 

 Special Reference to Triploid Mutants. Bull. Imp. SericuU. Exp. Sta. 

 Japan, 1: 317-369. 



73-113. 



