442 Vererbung, Variation, Mutation. 



Gives detailed data regarding tlie results obtained from 16 crosses of cotton 

 varieties. Thirty-seven distinct unit characters, having to do with either the 

 leaf, flower, ball, plant body, line or seed, are discussed. The following conclu- 

 sions are reached: 



"All varieties of cotton are intercrossed when grown on adjoining areas and 

 under natural conditions, and no pedigree can be considered after the variety 

 or strain has been subjected to the agencies which cause cross-fertilization. The 

 cotton plant coutains' some thirty or more pairs of heritable characters, all of 

 which seem to obey Mendel's law of dominance, segregation, and recombination, 

 in the crosses which have been studied. Dominance is incomplete for several 

 characters of the cotton plant, thus rendering the heterozygote intermediate and 

 resulting in a greater ränge of visible Variation in crosses which have two or 

 more characters correlated. Segregation into the 1 — 2—1, 3 — 1, 9 — 3—3—1, and 

 15 — 1 ratios is indicated in these experiments, but the exact theoretical propor- 

 tions occur in only a few instances, due either to too few individuals or to the 

 heterozygous condition of the parent stock. Intensification of characters in 

 crosses between Sea Island and Uplands is a very common phenomenon in the 

 F^ generation, but in the succeeding generations it gradually diminishes. Fluc- 

 tuation is infrequent in pure strains, but it is very common for characters of the 

 lint, even in apparently homozygous individuals, largely due to environmental 

 agencies, it seems. Selection within the variety brings about improvement in 

 solating the superior variations, but new strains seem to be the result of crossing, 

 inten tional or otherwise." Pearl (Orono). 



1235) Harris, J. A., A first study of the influence of the starvation 

 of the ascendants upon the characteristics of the descendants. I. 

 In: Amer. Natural. 46, S. 313—343, 1912. 



Experiments upon the influence of starvation and feeding on garden beans. 

 Three varieties of garden beans were used in these experiments, which number 

 about 21,000 individuals. The data here presented concern the number of pods 

 per plant. The plants were grown for two or three generations on "poor" agri- 

 cultural soil, and compared with others which were being grown on "good" 

 soil. The Statistical results seem to show a slight effect of the treatment ac- 

 corded the ancestors, but any such effect is not great enough to be detected 

 by the eye in the field. Gates (London). 



1236) Kastle, T. H. and Buckuer, G. D., Asymmetrie color resemblance 

 in the guinea pig. In: Amer. Natural. 46, S. 505 — 511, figs. 4, 1912. 



A guinea pig with certain asymmetrical colour markings, gave birth to three 

 young, one of which had the same peculiar markings as the mother but reversed, 

 that is, with corresponding patches of colour on the opposite side of the body. 



Gates (London). 



1237) Castle, W. E., On the inheritance of tricolor coat in guinea-pigs, 

 and its relation to Galton's law of ancestral heredity. In: Amer. 

 Natural. 46, S. 437—440, 1912. 



The tricolor race is yellow spotted with black and white. It has been 

 reared for centuries by the Peruvian natives but never breeds true. The Vari- 

 ation in Spotting is due to irregularity in distribution through the coat, of two 

 different substances, (l) the colour factor, and (2) the black factor, which have 

 been shown to be independant in heredity. They do not usually coincide in dis- 



