116 Varietäten, Descendenz, Hybriden. 



bau der Rispe oder die Art der Behaarung der Kornbasis des 

 Aussenkornes. Verf. meint, dass solche Merkmale nicht die Bedeu- 

 tung besitzen, die ihnen zugeschrieben wird, da veränderte 

 äussere Verhältnisse eine Veränderung derselben mit sich bringen, 

 welche die Unterschiede verwischt. Fruwirth. 



Cook, C. F., Mutative reversions in Cotton (Circ. N*^. 53, 

 Bureau of Plant Ind. U. S. Dep. Agr. p. 18. 1910.) 



The close similarities of the variant forms of many different 

 kinds of cotton is taken to indicate that ancestral characteristics 

 are returning to expression. This is more probable than that the 

 raany kinds of cotton "are engaged in the formation of closely 

 parallel series of new species". In other words, mutative reversions 

 in cotton are of rather common occurrence and are not confined to 

 Single characters but may bring whole series of more primitive 

 varietal characters into expression. These reversions do not depend 

 upon hybridization but occur in "pure-bred" Stocks and may be 

 aroused by new or unfavorable environmental conditions, such 

 diversities sometimes appearing when a stock is grown in a new 

 locality. This behavior seems to differ from the experience of several 

 breeders of "pure lines", the difference perhaps resulting from less 

 rigid selection. 



The variations of the different types of cotton have general 

 similarities and may be arranged in parallel series. The fact that 

 the progeny of mutative variations is more uniform, renders them 

 greatly superior to hybrids for breeding purposes, and it is consi- 

 dered possible that useful mutative reversions may thus be obtained 

 from later generations of dilute hybrid Stocks. Gates. 



Davis, B. M. , Notes on the behavior ofcertain hybrids 

 of Oenothera in the first generation. (Amer. Nat. XLIV. 

 p. 108—115. 1910.) 



In 1909 the following crosses were made: 1) gigas and Lamarc- 

 kiana, 2) }nuricata X S^SCi-s, 3) muricata X grandißora, 4) biennis X ' 

 grnndißora, 5) grandiflora X biennis. This preliminary account ot 

 the Fj outlines certain features of the hybrids. The results are in 

 general agreement with the previous experiments of de Vries and 

 others, twin hybrids being obtained in several cases, but the num- 

 bers are unfortunately rather small for dealing with plants which 

 show so much variability. Gates. 



East, E. M., Inheritance in potatoes. (Amer. Nat. XLIV. 

 p. 424—430. 1910.) 



The results are incomplete owing to a loss of part of the records 

 but the following probable results of crosses between potato varie- 

 ties are recorded. In stem color purple and green were found to 

 behave as a Mendelian pair. One purple variety was homozygous 

 while four others were found to be heterozygous, giving both purple 

 and green plants when selfed. Similarly three selfed varieties with 

 purple flowers gave purple and white individuals, and three white 

 flowered varieties bred true. In color of tubers purple potatoes 

 selfed gave (one varietj^) all purple; (two varieties) purple, red and 

 colorless; or (three varieties) purple and colorless. From these and 



