No. 4, February, 1922] GENETICS 267 



1738. Phillips, J. C. A further report on species crosses in birds. Genetics 6: 366- 

 383. 5 fig. 1921. — A continuation of crosses between various species of ducks on the one 

 hand and different species of pheasants on the other confirms the author's previous assump- 

 tion that segregation of characters in the 2nd hybrid generation is more pronounced in 

 closely related species and less pronounced in distantly related ones. The results are ex- 

 plained on the basis that a smaller number of character differences in the closely related 

 species permits the small numbers of offspring observed (not more than 100 in any case) to 

 include a larger proportion of the possible combinations than is the case with the large num 

 her of differences in widely differing species. In the latter cases only the very middle of the 

 distribution curve has been touched. Sex-linked characters were not observed. — //, G. May. 



1739. PixN, A. J. An experiment in selection. Agric. Gaz. New South Wales 32: 731. 

 1921. — In a series of (bin?) tuber selections of potato seed, 2 lots selected were second-growth 

 tubers broken from larger tubers. Yields from these 2 lots were more than 60 per cent greater 

 than secured from ordinary selected seed. The difference is ascribed largely to the fact that 

 second-growth tubers were immature. — L. R. Waldron. 



1740. Pitt, Frances. Notes on the genetic behaviour of certain characters in the polecat, 

 ferret, and in polecat-ferret hybrids. Jour. Genetics 11 : 99-115. 2 -pi., 1 fig. 1921. — The paper 

 deals with the genetic behavior of color and certain cranial characters in the ferret, Martes 

 furo Li., polecat Mnstela putorius L., and in their hybrids. The 2 species are compared as 

 regards color, facial markings, shape of head, cranial characters, disposition, and susceptibility 

 to disease. Fi hybrids show complete or very nearly complete dominance of the polecat 

 type except in cranial characters, and "when the hybrids were bred back to the polecat, 

 animals that were apparently pure polecats resulted." In the other back-cross polecat 

 coloration and temperament were soon lost. Evidence is presented that erythristic (red) 

 in varieties of polecat and ferret is a Mendelian character appearing with the loss of a "D" 

 (dark-brown) factor, which "seems to be correlated with increased size. . . ." The 

 author regards as most important "the indication of Mendelian inheritance of a structural 

 character (type of skull), and the evidence concerning a variation due to the loss of a factor 

 appearing and maintaining itself in nature" (the erythristic polecats). — A. W. Bellamy. 



1741. PoMBROY, C. S. Bud variation in Eleagnus. Jour. Heredity 12: 227-230. Fig. 19- 

 W. 1921. — The author refers to the common occurrence of variegated evergreen shrubs in 

 Southern California, and describes 2 variegated forms of Eleagnus pungens, E. pungens var. 

 aurea Servettaz and E. pungens var. Frederici variegata Servettaz, in a Riverside park. Ser- 

 vettaz is quoted on the difficulties of classifying species of Eleagnus because of extreme vari- 

 ation. — "There is no doubt of the bud origin of the variegated forms described and illustrated 

 herewith nor of bud generations under the continual asexual propagation of ordinary horti- 

 cultural practice." — C. S. Crandall. 



1742. Prbll, Hbinrich. Reine Kette, Genospezies und Stirps. [Pure chain, genospecies 

 and stirps.] Zeitschr. Indukt. Abstamm. u. Vererb. 26: 287-294. 1921. — The term pure chain 

 is applied to allogamous (bisexual or cross-fertilized) organisms in the same sense in which 

 pure line is used for autogamous organisms having the same genetical construction. A geno- 

 species contains individuals of only 1 pure line or 1 pure chain. Stirps is used for haploid 

 organisms as species is used for diploid organisms. — D. F. Jones. 



1743. Rawbs, a. N. Self -fertility and self -sterility in plums. Jour. Roy. Hort. Soc. 46: 

 353. 1921. — The author worked with plums in a greenhouse from which insects were excluded. 

 Pollination was accomplished by brushing stigmas with ripe stamens. The following varieties 

 proved self-sterile: Coe's Golden Drop, Decaisne, Grand Duke, Jefferson, Kirke's Blue, 

 Late Orange, Late Transparent Gage, Pond's Seedling, Comte d'Althan, Transparent Gage, 

 and Washington. The self-fertile varieties were: Dennistons Superb, Monarch and Czar; 

 and the partially self -fertile: Early Rivers, President, Prince Engelbert, and Stint. All 

 varieties were cross-fertile except Coe, Jefferson, President, and Late Orange; the last 2 

 appeared to be inter-sterile. No difference was observed in size and shape of fruit or stone 

 due to the kind of pollen used. — A. H. Hendrickson. 



