76 Vererbung, Variation, Mutation. 



Autoren über kräftigeren Wuchs der Bastarde, und speziell der Arbeiten Darwins, 

 wird gezeigt, daß es sich um allgemeine Gesetzmäßigkeiten handle. 



Der Wert der Kräftigung der Heterozygosis im Verlauf der Phylogenie ist 

 folgendermaßen gedacht: Es mußten Varianten auftreten, welche Kreuzbestäubung 

 begünstigten. Diese Varianten erzeugten durch Kreuzbestäubung Nachkommen, 

 welche kräftiger sein mußten als ihre durch Selbstbefruchtung entstandenen Ver- 

 wandten. Weil der Vorteil der Kreuzung fortdauerte, konnte der Kreuzbestäubungs- 

 mechanismus homozygot und fix werden. — Bei Selbstbefruchtern werden neue 

 Charaktere, die das Individuum schwächen, sofort eliminiert; bei Kreuzbefruch- 

 tung können schwache Genotypen erhalten bleiben durch die Kraft, welche sie 

 durch Kreuzung mit anderen Genotypen erhalten. Schüepp (München). 



200) Trow, A.H. (Cardiff, University College), Forms of Reduplication — 

 primary and secondary. In: Journ. of Genetics, Bd. 4, S. 313 — 324, 1913. 



Bateson and Punnett have suggested (Journ. of Gen. 1, p. 293) that ga- 

 metic coupling may be due to reduplication of cells bearing the "coupled" cha- 

 racters, so giving ratios of the general type 2" — 1 : 1 : 1 : 2^" — 1. The author 

 points out that other ratios, e. g. 6 : 1 : 1 : 6 have been found, and that these 

 may be due not to primary coupling between two characters, but to secondary 

 coupling, caused by the fact that each is coupled directly with a third. If there 

 are three pairs of characters, A, a ; B, b, C, c, in which the coupling between A 

 and B (and a and b) is as n : 1, that between A and C is as m : 1, he shows 

 that the apparent coupling between B and C is as um + 1 : n -f m. He works 

 out this idea fully, and points out that almost any type of coupling m^y arise 

 on Bateson and Punnett's hypothesis. Doncaster (Cambridge). 



201) Davis, B. M. (Pennsylvania University), Was Lamarck's evening prim- 

 rose (Oenofliera Lamarciciana Seringe) a form of Oenothera grandi- 

 flora Solander? In: Bull. Torrey Bot. Club, Bd. 39, S. 519 — 533, pls. 37—39, 

 1912. 



DiscLission of three type herbarium sheets in the Museum d'Histoire Na- 

 turelle, Paris, based second-hand on observations of Miss Eastwood. De Vries 

 (Mutationstheorie) concluded from personal examination that the first two sheets 

 agreed in general, though not in all particulars, with the 0. lamarciciana of his cul- 

 tures, while the third he referred to 0. grandiflora. Davis attempts to show that 

 specimen (l) is a form of 0. grandiflora^ that (2) is a form of 0. hürmis, and (3) 

 he thinks cannot be identified. In 1911 the reviewer (Early histico-botanical re- 

 cords of the Oenotheras. Proc. Iowa Acad. Sei. 1910, p. 111) pointed out certain 

 discrepancies between the Lamarck-Poiret description of 0. lamarcUana and the 

 characters of the 0. lamarcMana of de Vries' cultures. Davis, who falls to refer 

 to this, attempts to show that the specimen (l) in question really belongs in 

 0. grandiflora Solander and not to the O.Iamarchiana of de Vries. Since however, 

 many races, both of lamarckiana and grandiflora are now known from cultures, 

 the question is a difficult one to decide, depending not merely on the characters 

 of the type specimen but also on the large array of other races, unless, as is 

 highly imi^robable, speciraens (l) and (3) are identical. 



Regarding specimen (2), Davis has doubtless done well to accept the prin- 

 ciple (suggested some time ago by the reviewer) that flower-size is a character 

 of fundamental importance in delimiting the species, and therefore to refer spe- 

 cimen (2), which has small flowers, to 0. hiennis. 



The third specimen (3) is obviously from the photograph, to one who is fa- 



