262 Varietäten, Descendenz, Hybriden. 



considered, and it is concluded that sex cannot be determined 

 directly by the presence or absence of a factor which merely 

 determines whether an ovary or a testis shall develop. but that the 

 determining factor causes a certain type of metaboiism, which in 

 turn leads to the production of one sex or the other. 



Agnes Arber (Cambridge). 



Gertz, O., Om Variationen i antalet kalkblad hos Caltha 

 palustris L. — Ett tillägg. [lieber die Variation der Zahl 

 der Perigonblätter bei Caltha palustris'L. — Ein Nachtrag]. 

 (Bot. Notiser. p. 227—228. 1914.) 



Die von Falck aufgestellte Regel, dass Caltha palustris eine 

 geringere Anzahl Perigonblätter hat, je nördlicher sie wächst, wurde 

 vom Verf. bei einer früheren Gelegenheit (vgl. Bot. Centralbl., Bd. 

 126, p. 10, 1914) und dann durch Jensens Untersuchungen in 

 Dänemark (Flora og Fauna, 1914, p. 117) bestätigt. In einer am 

 I.Juni 1913 untersuchten Serie aus Schonen fand Verf. Zahlen- 

 werte, die sich mehr als die von Jensen am 24. April 1914 in 

 Dänemark beobachteten den in Deutschland und Holland 

 gefundenen näherten. Dies sucht Verf. in der Weise zu erklären, 

 dass eine Verschiebung in der Richtung gegen Pleomerie bei 

 Caltha sich geltend mache in dem Masse, als die Vegetationsbe- 

 dingungen, sei es durch Erhöhung der täglichen Mitteltemperatur 

 an ein und demselben Standort, sei es infolge einer südlicheren 

 Lage, optimaler werden. Grevillius (Kempen a Rh.). 



Richardsoll, C. W., A Preliminary Note on the Genetics- 

 of Fmgaria. (Journ. of Genetics III. 3. p. 171-177. Feb. 1914.) 



The paper deals with results obtained on crossing varieties of 

 Fragaria. 



(a) F. vesca. The presence of runners, the red colour of the 

 fruit, and the trifoliate type of leaf were found to be markedly 

 dominant over absence of runners, white coloured fruit and mono- 

 phyllous leaves respectively. 



(b) Garden hybrids. 



It was found possible to cross garden varieties of Strawberry 

 with F. vesca though the yield of seed was very poor. 



Various "perpetual" varieties were selfed giving an F^ in which 

 the „perpetuals" out numbered markedly the "non perpetuals". 



A "non-perpetual" crossed with a „perpetual" gave 24 "per- 

 petuals" and 53 non perpetuals in F^. 



Varying sexual arrangements are found in Fragaria. Grosses 

 between pure $ and pure (/ resulted in F^, in a proportion of 5 in 

 addition to </ and 5 plants. 



Pure $ crossed with g gave all three forms in one case but 

 no ^ in another. W. Neilson Jones. 



Salmon, E. S., On the appearance of Sterile "Dwarfs" in 

 Hunntlus Litpulus L. (Journ. of Genetics. Vol. III. 3. p. 195—200. 

 Feb. 1914.) 



Among the offepring from crosses between cultivated varieties 

 of female plants and individual male plants were some differing 



