194 GENETICS [Bot. Absts., Vol. V, 



1475. Cooley, Charles H. A discussion of Popenoe and Johnson's "Applied eugenics" 

 and the question of heredity vs. environment. Jour. Heredity 11: 80-81. Feb., 1920. 



1476. Correns, C. Fortsetzung der Versuche zur experimentellen Verschiebung des 

 Geschlechtsverbaltnisses. [Continuation of experiments on artificial shifting of sex relations.] 

 Sitzungsber. Preuss. Akad. Wiss. Berlin 1918: 1175-1180. 3 fig. 1918. 



1477. Coulter, Merle C. Inheritance of aleurone color in maze. Bot. Gaz. 69: 407-^425. 

 May, 1920. — An attempt was made to test the certainty with which predicted aleurone ratios 

 would be fulfilled in complicated crosses. Crosses were made involving the Rr Cc and Pp 

 factors in such a way as to require eight different ratios. The general conclusion is reached 

 that the expectation in these cases is reasonably fulfilled. Seeds of different shades of color 

 were separated and planted to determine whether it was possible to recognize genotypes by 

 the intensity of the color. The author concludes that with experience genotypes may be 

 separated by this method, particularly among red seeds. The inheritance of faintly colored 

 or parti-colored seeds was studied. It is assumed that such seeds lack the aleurone factor C 

 but have some partial substitute which is very erratic in its effect on the expression of color. 

 An unusual case is reported where a plant known to have the factorial composition Pp rr Cc 

 gave, when selfed, an ear with a perfect ratio of 9 colored to 7 white seeds. It is believed in 

 this case that some unusual condition is present which produces purple aleurone when com- 

 bined with the factors PC but colorless aleurone in combination with C only. Practically all 

 the grains on this ear had irregularly split pericarps and when planted germinated slowly or 

 not at all with a subsequent slow and stunted growth, suggesting that the aleurone ratio may 

 be due to pathological causes. Crosses in which Emerson's i2-tester was used as the male 

 parent and C-tester as the female parent {PPRRcc X PPrrCC) were found to have only self 

 purple seeds but when the parentage was reversed (PPrrCC X PPRRcc) all the seeds were 

 mottled. This confirms the results of Emerson from whom the material was received. In 

 various crosses of Emerson's C and R testers with material obtained from East, the author 

 concludes that these investigators have given similar symbols to the same set of factors. A 

 study of mottling led to the conclusion that it can appear only when the R aleurone factor 

 enters the seed from the male parent and then only when some other condition is present. 

 This other condition was found in Emerson's C-tester. A very small percentage of mottled 

 seeds is obtained where no mottling is to be expected, in some crosses involving .ft-tester. 

 Such mottled seeds are believed to differ genetically from the mottling in the crosses involving 

 C-tester. — It was found that there were no differences in the inheritance of aleurone color 

 between inflorescences on the main stalk and suckers, but there was evidence, not given, that 

 differences might be expected in the inheritance of plant colors, particularly chlorophyll, 

 between the main culm and lateral branches. — A further test of the variability in inheritance 

 which may occur between different parts of the same plant was obtained by self-pollinating 

 both ears of two-eared plants. In most cases the two ears were reasonably alike but in some 

 instances significant differences were found. The agreement between the two ears of the 

 same plant is especially poor where faint aleurone color is involved. — The chance distribution 

 of the different-colored seeds on the ear was tested and found to hold for starchy-sweet and 

 colored-colorless but on ears where less than 10 per cent of the grains were particolored the 

 majority of spotted grains were found in groups of 4 or 5, indicating the influence of local con- 

 ditions. With respect to this phenonemon the author believes that local conditions on the 

 ear do not determine but merely limit the appearance of particolored aleurone.— J. H . 

 Kempton. 



1478. Cowgill, H. B. Cross-pollination of sugar cane. Jour. Dept. Agric. Porto Rico 

 3: 1-5. Jan., 1919. — Method used at Insular Experiment Station of Porto Rico is satisfactory 

 and many seedlings are produced. Bags are made of cheese cloth 48 inches long and 18 wide, 

 held extended by heavy wire rings sewed into them. Rings placed one at top and other 16 

 inches from bottom so that a skirt of 16 inches is left to be drawn in and tied about stems 

 of panicles. Bags are supported over panicles by means of bamboo poles set in ground with 

 cross-bar at top. Poles are set to windward side of stools just before panicles "shoot;" 



