Vererbung, Variation, Mutation. 451 



Untersuchungen über Kreuzung von lockerährigem „Noe"-Sommerweizen und dicht- 

 äbrigem, sog. Kölbel- Sommerweizen: Dichtährigkeit dominierend. Vergleichung des 

 Korngewichts ergab Großkörnigkeit als recessives Merkmal. Spontan traten auf weiß- 

 körnige und begrannte Pflanzen, ferner solche mit bedeutender Halmlänge, die aber in 

 den folgenden Generationen allmählich zurückging. Loeser (Dillingen a. d. Saar). 



1383) Federley, Harry, Sur un cas d'heredite gynephore dans une 

 espece de Papille n. In: IV® Conference Intern, de Genetique, Paris 1911; 

 Compt. rend. et Rapports, S. 469 — 477, 1913. 



En croisant deux especes de Papillons appartenant au genre Pygoera (P. cur- 

 tula c? et P. anaclwrcta $) et ne montrant aucun dimorpliisme sexuel, on obtient 

 des individus sexues qui se distinguent dejä nettement dans la petite chenille. 

 Au cours d'experiences repetees sur des exemplaires de Pyficera atteints de la 

 maladie de l'hemolymphe, l'auteur a pu montrer qu'il etait impossible d'expliquer 

 l'heredite de cette maladie ä l'aide de la loi de Mendel; 11 n'a pu, d'ailleurs, 

 jusqu'ici, fournir une explication satisfaisante de la transmission de cette maladie. 



Louis Germain (Paris). 



1384) Tanaka, Y. (Sapporo, Japan, University), A study of Mendelian fac- 

 tors in the Silkworm, Bomhyx mori\ and Gametic coupling and re- 

 pulsion in Silkworms. In: Journal of College of Agriculture, Tolioku Im- 

 perial University, Sapporo, Japan, Bd. V, Heft IV — V, S. 91 — 148, 2 plates, 

 1913. 



Breeding experiments with silkworms show that tliere are several larval 

 characters whicli behave as Mendelian units. Those recognised by the author 

 are striping (S), zebra-pattern (Z), moricaud (^M), Normal or Common (N), 

 the absence of all of which gives piain. Por cocoon-colours (and larval blood- 

 colour) there are yellow (Y) the absence of which (y) gives white, and an In- 

 hibitor (I), w^hich prevents the appearance of yellow^ though Y be present. S, Z, 

 and M are each epistatic to N; these four factors are of course each dominant 

 to piain. The experiments of Toyama and others indicate that S, Z, and M are 

 none of them completely epistatic over one another. The most interesting portiou 

 of the observations described is concerned with gametic coupling and repulsion. 

 When introduced into the heterozygote from different parents, it w^as found 

 that the factors N and Y exhibited complete repulsion, so that the heterozygote 

 NnYy produces two kinds of gametes only, Ny and nY. Similarly there may 

 be complete repulsion between S and Y, the heterozygote SsYy producing ga- 

 metes Sy and sY. In the case of the triple heterozygote SsNnYy, there was 

 complete repulsion between S und N, so that only gametes SnY, Sny, sNY, 

 sNy were produced. At the same time there were indications of partial coupl- 

 ing between S and Y, in the ratio of about 7SY: iSy. This result might also 

 be accounted for by partial repulsion between N and Y, but the fact that partial 

 or complete coupling S and Y was found in other cases in which N was not 

 present, makes the author incline to the former alternative. 



Doncaster (Cambridge). 



1385) Houwiuk, K., Experiences pratiquees pour obtenir des varietes 

 fixes et durables dans les races de volailles rustiques et dans les 

 races italiennes importees. In: IV® Conference Intern, de Genetique, Paris 

 1911; Compt. rend. et Rapports, S. 524— 533, 40 fig., 1913. 



L'auteur s'est livre ä un tres grand nombre d'experiences concernant les 

 caracteres transmis par heredite chez diverses varietes de poules domestiques. II 



29* 



