Vererbung, Variation, Mutation. 263 



from the affected male through his daughters to some of tlieir sons; there is no 

 case of an affected female, nor of direct transmission from father to child, nor 

 of transmission by an unaffected male. It is thus strictly sex-limited. There is 

 a considerable excess of affected over unaffected males, and a smaller excess of 

 male over female children, in affected families. The disease is associated with 

 some other abnormalities. It is pointed out that if the male has one sex-chro- 

 mosome, and the female two, the transmission is explicable by regarding the 

 disease as being due to a defect in the sex-chromosome. 



Doncaster (Cambridge). 



825) Crzellit/er, A., Die Vererbung von Augenleiden. In: Umschau, S. 456— 458, 

 1913. 



Beobachtet wurden 768 Familien. Von Einfluß ist Geschlecht und Blutsverwandtschaft. 



Loeser (Dillingen a. d. Saar). 



826) Wille, N., Über die Veränderungen der Pflanzen in nördlichen 

 Breiten. Eine Antwort an R. Semon. In: Biol. Centralbl., Bd. XXXIII, 

 Heft 5, S. 245—254, 1913. 



Polemik gegen Semon. Wille begründet seine Kritik der Versuche Schü- 

 be 1 e rs mit dem Hinweis auf die außerordentlichen Witterungsverhältnisse während 

 der drei Versuchssommer 1857 — 1859. Er bringt die Temperatur- und Regen- 

 tabellen für Christiania für die Sommermonate aller Jahre von 1838 — 1908. Ein- 

 gehende Nachuntersuchungen über die Länge der Vegetationszeit einer Pflanze 

 unter verschiedenen Breitegraden sind von Baur in Berlin, Nilsson-Ehle in 

 Svalöff, Gran und Christie in Norwegen mit „reinen Linien" organisiert worden. 

 Das Ergebnis dieser Versuche bleibt abzuwarten. Schüepp (München). 



827) Hedrick, U. P. and Howe, G. H., Apples: Old and New. In: Bulletin 

 Nr. 361, New York Agr. Exp. Sta., S. 79—135, 1913. 



A large number of varieties of apples have been carefully compared with 

 early records of the same variety and the results show that there is no foun- 

 dation in the idea that degeneration of a variety after a time takes place. Ne- 

 glect, unsuitable soil, insects and disease are the factors which cause a wearing 

 out of iudividual trees, but under favorable conditions the varieties will show 

 HO cliange or degeneration. 



In Order that a foundation might be laid upon which breeding for disease 

 resisting strains could be carried on, a knowledge of the iramunities and suscep- 

 tibilities of existing varieties is necessary. A list of varieties of apples, which at 

 the Geneva Experiment Station are more or less resistant or susceptible to two 

 •diseases — apple scab {Ventiiria inacqualis) and apple blight {Bacillus amylovo- 

 riis) is given. 



The causes of seedlessness are discussed. A study of seedlessness of apples 

 at the Geneva Station shows that the abortion or malformation of one or seve- 

 ral of the floral organs accompanies most of the seedless apples. A tendency to 

 decrease in size with seedlessness is noted, the varieties are usually productive, 

 the flavor is below the mark (probably through accident) and the cores are 

 usually small and partly, or, in a few cases, wholly absent. Pearl (Orono). 



828) Tuillemiu, P., La pelorie et les anomalies connexes d'origin 

 gamogemmique. In: Annales des Sc. Natur. Botanique, IX^ Serie, Bd. 16, 

 Heft 3—4, S. 187—277, 1912. 



La gamogemmie est, jusqu'ici, le seul facteur de Forganisation intime qui 

 puisse etre considere comme cause de la pelorie, aussi bien que de l'actinomor- 

 phie habituelle des genres appartenant ä des families zygomorphes. 



