No. 4, February, 1922] GENETICS 257 



RR pp, white. WW RR PP represents the basic type, carmine in color; w, the difference 

 from it which gives white, irrespective of which members of the pair occupy the R or P loci; 

 p, that which gives pink; and /•, that which changes pink to red. — In reciprocal crosses between 

 Cuba (white) and viacrophylla (I'ed), 150 Fi plants were pink-flowered. The F2 plants gave 

 totals of 113 pink, 44 red, and 42 white, the expected numbers, based on a 9: 3: 4 ratio, being 

 112: 37: 50. Another form, purpurea, exhibits a flower color somewhat darker and more 

 intense than viacrophylla. In order to demonstrate the difference in behavior between these 



2 reds, a number of parallel crosses were made between them and other Tabacum varieties. 

 When macrophylla was crossed with angustifolia (light pink), with Cavala (pinkish), and with 

 Cuba (white), all the Fi plants were pink-flowered. When purpurea was crossed with these 



3 forms, the Fi plants were carmine-flowered. Further crosses of Cuba and purpurea gave 

 Fo totals of 190 carmine, 48 pink, 107 white, further substantiating the difference between 

 viacrophylla and purpurea. This also supports the belief that the dominant carmine de- 

 scribed by Allard was genetically different from the recessive red previously described by 

 the authors. — A. N. Wilcox. 



1693. Collins, J. L. The new craft of making plants to order. Gard. Mag. 33: 372-374. 

 2 fig. 1921. — This is a rather non-technical review of the method of producing new plants 

 by applying genetic principles. — H. E. Breivbaker. 



1694. Collins, J. L. The new craft of making plants to order. II. Increased crop through 

 hybrid seed. Gard. Mag. 34: 40-41. S fig. 1921. — Commercial possibilities are pointed out. 

 — H. E. Brewbaker. 



1695. CoviLLE, Frederick V. A new hybrid — the Katherine blueberry. Jour. Heredity 

 11: Frontispiece. 1920. — This is the best of 3,000 hybrids from crossing 2 selected strains 

 of highbush blueberry. Over 97 per cent of the berries range between J and | inch in diam- 

 eter; and they have a delicious flavor, firm texture, and small seeds. This variety will soon 

 be on the market. — Merle C. Coulter. 



1696. Daniel, Lucien. Recherches sur la greflfe des Solanum. [Studies on Solanum 

 grafts.] Compt. Rend. Acad. Sci. Paris 171: 1074-1076. 1920. — Potato grafts of the variety 

 Fluke placed upon tomato and egg-plant produced aerial tubers. The aerial tubers from the 

 potato-tomato graft produced plants which were all alike and resembled the variety Fluke. 

 The aerial tubers from the potato-egg-plant graft produced plants which behaved as inter- 

 mediates, and matured much later than the potato-tomato grafts. Three plants produced 

 both aerial and subterranean tubers, as many of the latter being obtained as from normal 

 plants. The plants producing both subterranean and aerial tubers were not attacked by 

 Phytophtora infestans. Several grafts of egg-plant upon tomato produced fruits of tomato 

 shape, but with the color of the egg-plant. Other grafts showed no change. — H. K. Hayes. 



1697. Davis, H. P. Were the black-and-white Holsteins originally red-and white? Jour. 

 Heredity 11: 155. 1920. — The author reports the occurrence of a Holstein calf with red-and- 

 white markings, which leads him to believe that the ancestors of Holstein-Friesians were 

 probably red-and-white. He desires information concerning this problem and contact with 

 anyone having a red-and-white heifer. — E. Roberts. 



1698. Detlefsen, J. A. A herd of albino cattle. Jour. Heredity U: 378-379. Fig. 26- 

 27. 1920. — The author describes a herd of pink-eyed white cattle at Mora, Minnesota. The 

 owners' statements as to the mode of origin and later breeding do not harmonize well with 

 any simple explanation of the mode of inheritance of albinism, and agree best with the hy- 

 pothesis that it is recessive. The original albinos are said to have come from mating a Holstein 

 bull to grade Holstein cows. — Sewall Wright. 



1699. Dunn, L. C. Unit character variation in rodents. Jour. ]Mammalogy 2: 125- 

 140. 1921. — Comparison is made between color variations studied e.xperimentally in rodents 



