February, 1920] GENETICS 33 



232. Blakeslee, A. F. A unifoliolate mutation in the Adzuki bean. Jour. Heredity 10: 

 153-155. Fig. 2. Apr., 1919.— Sec Bot. Abets. 3, Entry 980. 



233. Brierly, W. B. Experimental studies in the specific value of morphological characters 

 in the fungi. Proc. Linnean Soc. 1918: 55-56. 1918. 



234. Broderick, F. W. Hardy apples and plums for the Canadian Northwest. Minnesota 

 Hortic. 46: 393-399. / pi., 1 fig. Nov. 1918.— Discussion of development of hardy apples and 

 plums for Canadian northwest. Mention is made of the results of prominent horticulturists in 

 work. A list of most promising apple and plum varieties is included. Crosses of hardy 

 standard varieties with Pyrus baccata proved to be hardy. In the plum, selections were 

 made from native wild seedlings. In general three methods have been used in obtaining 

 hardy varieties: crossing hardy varieties and selecting the best seedlings; selections of best 

 types from the wild; and importation.— M. J . Dorsey. 



235. Castle, W. E. Piebald rats and the theory of genes. Proc. Nation. Acad. Sci. U. 

 S. Amer. 5 : 126-130. 1 fig. Apr., 1919— Two conceptions of heredity are contrasted. "Unit- 

 characters" (character differences acting as units in heredity), may show variation, as result 

 of crossing or of selection. This indicates that the hereditary unit varies. On other hand 

 it is supposed that hereditary unit, gene, is invariable, except for rare and sudden changes, 

 mutations, and that variation in character is due to recombinations of other genes, modifiers. 

 Hooding character in rats acts as recessive unit difference from self, but shows great hereditary 

 variation. Plus-selected race with mean grade of + 3.73 and standard deviation of 0.36 was 

 thrice crossed and extracted from wild self. Mean grade was reduced to + 3.04 with standard 

 deviation of 0.64. Minus-selected race with mean grade of — 2.63 and standard deviation of 

 0.27 was thrice crossed and extracted from wild self. Mean grade was raised to + 2.55 (in 

 one family of 14 hooded to -f- 3.05) with standard deviation of 0.66. Standard deviation was 

 high at first extraction and somewhat reduced at third. These facts indicate that the varia- 

 bility of the hooded character is due to residual heredity or modifying factors rather than to 

 changes in hooded gene proper. — P. W. Whiting. 



236. Castle, W. E. Siamese, an albinistic color variation in cats. Amer. Nat. 53: 265- 

 268. May-June, 1919.— Complete albinism occurs in rats, mice, and rabbits. Partial albin- 

 ism of "Himalayan" type occurs in guinea-pigs and rabbits, of "red-eyed" and "dilute" 

 types in guinea-pigs, and of "ruby-eyed" type in rats. Genetic locus for albinism is prob- 

 ably homologous in different rodents. "White-spotting" and "pink-eye" are not allelo- 

 morphic with albinism. Blondism in man may, according to Wright, be partial albinism. 

 Partial albinism acts as recessive, is more pronounced in young, reduces pigment in eye, and 

 tends to suppress or eliminate yellow pigment in coat. Siamese dilution in cats has these 

 characteristics except that it is not completely recessive. Doctor in England furnishes data 

 in reference to crosses with other strains. First generation animals from black are almost 

 black, but incline toward seal brown as in ears of Siamese. Other crosses produce white or 

 yellow spotting according to expectation. Siamese voice and "cross-eyes" are more or less 

 dominant. An Fi female crossed to pure Siamese gave three Siamese pure in all respects. 

 Other types were not mentioned. "Blue-pointed" Siamese were obtained, presumably from 

 crosses with maltese. Siamese, as far as reported, is always non-agouti. Agouti forms could 

 probably be obtained by crossing to tabby. — P. W. Whiting. 



237. Cole, Leon J., and Fraxk J. Kelley. Studies on inheritance in pigeons. III. 

 Description and linkage relations of two sex-linked characters. Genetics 4: 1S3-203. Mar., 

 1919— See Bot. Absts. 3, Entry 2102. 



238. Collins, G. N. A fossil ear of maize. Jour. Heredity 10: 170-172. Fig. 7. Apr., 

 1919— See Bot. Absts. 3, Entry 984. 



239. Collins, G. N. Intolerance of maize to self-fertilization. Jour. Washington [D. C] 

 Acad. Sci. 9: 309-312. June 4, 1919— See Bot. Absts. 3. Entry 607. 



