48 



THE AMEBIC AN NATURALIST [Vol.XLVIII 



about 22 leaves. If planting is delayed until the seedling 

 is eight or ten inches high, there is a different state of 

 affairs. Development is arrested, the plant pauses to ad- 

 just itself to the change. It soon recovers and continues 

 its normal ontogeny, but the period of reduced growth 

 has left an ineffaceable record. Several of the leaves — 

 among them the more valuable leaves — have been so 

 affected during this readjustment, that they develop to 

 only a fraction the size that they should attain because 

 the internodes between them are so short, due to the con- 

 stricted development that normal metabolism does not 

 occur. Thus there is a loss of one or two leaves, which 

 on several acres of tobacco may make the difference be- 

 tween profit and loss. Hence, the grower should not de- 

 lay setting his plants in the field until they have become 

 overgrown in the seed bed. 



March, 1913 



LITERATURE CITED 

 Davis, B. M. Genetical Studies in (Enothera, III. Amee. Nat., 46: 377- 

 427. 1912. 



East, E. M. Inheritance of Flower Size in Crosses between Nicotiana 



Species. Bot. Gaz., 55: 177-188. 1913. 

 East, E. M., and Hayes, H. K. Inheritance in Maize. Conn. Agr. Exp. Sta. 



Bull. 167: 1-142. 1911. 

 Garner, W. W. Some Observations on Tobacco Breeding. Ann. Rpt. Amer. 



Hayes, H. K. Correlation and Inheritance in Nicotiana Talacum. Conn. 



Agr. Exp. Sta. Bull. 171 : 1-45. 1912. 

 Heribert-Nilsson, N. Die Variability der Oenothera Lamar cTciana und das 



Problem der Mutation. Ztschr. Abstam. u. Vereb., 8 : 89-231. 1912. 

 Jennings, H. S. Heredity, Variation and Evolution in Protozoa, I. Jour. 



Exp. Zool., 5: 577-632. 1908. 

 . Heredity, Variation and Evolution in Protozoa, II. Proc. Amer. 



jugation of P&ameckm, Jour. Exp. Zool, 11: 1-133. 1911. 

 Johannsen, W. Uber Erblichkeit in Populationen und in reinen Linien. 



Jena, Gustav Fischer, pp. 1-515. 1903. 

 Pearl, Raymond. Inheritance of Fecundity in the Domestic Fowl. Amer. 



Nat., 45: 321-345. 1911. 

 Shamel, A. D. New Tobacco Varieties. Yearbook U. S. Dept. Agr., 1906: 



387-404. 1907. 



Tammes, Tine. Das Verhalten fluktuierend variierender Merkmale bei der 

 Bastard ierung. Pec. Trav. Bot. Nierl., 8: 201-288. 1911. 



