522 Varietäten etc. — Physiologie. 



Harris, J. A.. Hallett's method ofbreeding and the pure 

 line theory. (Amer. Breeders Magazine. IV. p. 32—24. 1913.) 



In giving some interesting quotations from Hallett's papers 

 about improvement of cereals and other foodplants, the author 

 discusses Hallett's views about the working and effectiveness of 

 selection in wheat grains and in potatotubers. Especially may be 

 mentioned, the following words of the author: "Two things are 

 clear from this quotation. First, Hallett used fifty years ago the 

 "ear to row" test so often emphasized as a modern method. Second, 

 bis method of selection in wheat, a generall}?^ seif fertilized plant, 

 was essentially a method of improvement by selection within the 

 pure line!" The writer lays "this question of the critical value of 

 Hallett's opinions aside," but "one must admit that if a man's 

 results are to be cited in evidence at all they should be correctly 

 set forth." M. J. Sirks (Haarlem). 



Hayes, H. K., Variation in tobacco. (Journ. of Hereditv. V. 

 p. 40-46. 1914.) 



In recent years man}^ foreign types of tobacco have been grown 

 from imported seed in the United States. In most cases these 

 have proved very variable in their characters during the early years 

 of their development and this has led to a common belief that a 

 breaking up of type is caused by the change of environment when 

 seed of southern tobacco is grown in the north. Shamel believed 

 two efficient means of inducing variability as a source of new types 

 to be: change of environment and crossing. Hasselbring at the 

 other side denied the breaking up of type in a number of "pure 

 lines" which were grown in Cuba and in Michigan; whatever 

 modifications did appear due to the change of environment, appeared 

 alike in all of the plants of a given strain. 



In 1908 the writer became interested in the study of heredity 

 in tobacco and has had many opportunities to observe the effects 

 of environment on tobacco characters. The general conclusions from 

 this work are that environment is of great importance in any System 

 of tobacco breeding, and quantitative characters and especially 

 quality of cured leaf are in a large measure dependent on this 

 feature. Change of environment, however, does not cause a breaking 

 up of type, and whatever variations occur due to environment 

 appear alike in all plants of a particular type. 



Heredity is the second important factor and poor types will 

 give unfavorable results even under the best environmental conditions. 

 Any System of tobacco breeding must take both heredit}^ and envi- 

 ronment into account. 



The only known means of producing variability as a source of 

 new types is by crossing. The number of new forms which will 

 appear due to a particular cross will depend on the number of 

 germinal characters by which the parent plants differ. As interesting 

 instance of cross the author mentions a hybrid between a Cuban 

 Havana tobacco which has very large leaves but only a few of them, 

 with a Sumatra type, which has numerous leaves, but only small 

 ones. A very good form, Halladay Havana, has been grown from 

 the offspring of this crossing. M. J. Sirks (Haarlem). 



Figdor, W., Ueber die panaschierten und dimorphen 

 Laubblätter einer Kulturform der Fiinkia lancifolia 



