450 Vererbung, Variation, Mutation. 



Prozessen. Es würde also eine besondere Art von determinierter somatischer In- 

 duktion vorliegen. Nicht als ob nun eine unbegrenzte Zahl exogener Abänderun- 

 gen in den Keimzellen sich wiederspiegeln könnte, vielmehr ist anzunehmen, daß 

 nur für eine bestimmte und begrenzte Zahl von exogenen Abände- 

 rungen eine latente Potenz in den Keimzellen sich vorfindet. Vielleicht 

 bedingt durch die Konstitution des Artplasmas an sich, also etwa vergleichbar 

 den aus der Konstitution ableitbaren Isomerien einer organischen Verbindung. 



Hinweise auf tatsächliches Vorhandensein virtueller Potenzen sieht Verf. in 

 dem Vorkommen derselben Entwicklungsmöglichkeiten bei Angehörigen ver- 

 schiedener Tierklassen (z. B. Albinismus), sodann in den generellen Potenzen 

 engerer Verwandtschaftsgruppen (Zebrastreif ung der Equiden) endlich in den als 

 „Transversionen" bezeichneten Möglichkeiten der Entwicklung (bei Tauben auf- 

 tretende Schwimmhäute; Auftreten gekreuzter Schnäbel außerhalb der Gattung 

 Loxla. und umgekehrt Vorkommen von Varietäten von Loxia curvirostra mit un- 

 gekreuztem Schnabel) sowie in den Fällen transgressiver Variabilität (de Vries). 



Wenn am Fawessa-Flügel nach Einwirkung extremer Reize auf das Puppen- 

 stadium die beiden Vorderrandflecken verschmelzen, oder wenn dem schwarzen 

 Alpensalamander die für den Feuersalamander charakteristische Art und Weise 

 der Fortpflanzung künstlich aufgezwungen wird, so könnte es sich hierbei eben 

 um die Weckung solcher latent vorhandenen Potenzen handeln. Daiber. 



1192) Stöckard, €. K., The effect on the offspring of intoxicating the 

 male parent and the transmission of the defects to subsequent 

 generations. In: Amer. Natural., Bd. 47, S. 641—682, 1913. 



The experiments were made with male guinea-pigs, to determine the effect 

 of alcohol on its reproductive organs and on subsequently produced offspring. 

 The important researches of 0. Hertwig, his son and daughter, Poll, and others 

 were first described, in which they studied the effects of radium emanations on 

 the sperm and eggs of frogs and other animals and on the subsequent embryos. 

 The chromatin of either egg or sperm could be made to degenerate by sufficient 

 treatment, the other pronucleus in such cases forming the whole of the nuclei of 

 the embryo. The author used healthy male guinea-pigs which had been nearly 

 intoxicated with alcohol nearly every day for, in some cases, a period of 32 months: 

 The results show that an alcoholized male almost invariably begets defec- 

 tive offspring when bred to a vigorous healthy female. The alcohol was admi- 

 nistered by means of Inhalation, producing drowsiness and Stupor and in some 

 cases viciousness. The resulting off spring: of 69 young, 54 of which were born 

 alive, only 33 survived, and many of these were small, excitable animals. When 

 bred together the latter gave defective offspring in several cases, though they 

 had not been treated with alcohol. Thus the paternal germ cells may be modi- 

 fied by chemical treatment to such a degree that the male will beget abnormal 

 offspring which again transrait the defect. Alcoholized females mated with nor- 

 mal males gave a better result by 1 6*^/0 • When alcoholized males and females 

 were mated together the effects are slightly more marked than when only one 

 parent is so treated. The defects shown by the offspring are general in type, 

 not specific, the central nervous System and sense organs being most affected. 

 The inheritance of these defects is explained by the fact that the offspring 

 "contains in every cell of its body elements derived from the weak or injured 

 male pronucleus". Nevertheless, this is not interpreted as "transmission of ac- 

 quired characters", for new characters are not transmitted but merely a weake- 

 ned condition of the cells. Gates. 



