No. 2, March, 1921] 



GENETICS 127 



same species at another place there was a single mode at 21 ligules. Numerous foliage varia- 

 tions observed in the drained-pond colony and examination of achenes from ligulate flowers 

 of 25 individuals showed that two had the well-developed crown or pappus characteristic of 

 other species of the genus, two had less-developed pappus, while 21 had naked fruits typical 

 of L. vulgare Lam. — James P. Kelly. 



861. Blaringhem, L. Production par traumatisme d'une forme nouvelle de Mais S cary- 

 opses multiples, Zea Mays var. polysperma. [The traumatic origin of a new form of maize with 

 multiple fruits, Zea Mays var. polysperma.] Compt. Rend. Acad. Sci. Paris 170:677-679. 

 1920.— Hereditary line of maize with a varying percentage of double and sometimes triple 

 grains (caryopses) has been isolated from the author's original teratological cultures in 

 which the main stalk of the plant had been injured. A description of this new strain, called 

 Z. Mays var. polysperma, is given. A correlation between the double grains on the ear and 

 a corresponding union of the spikelets on the staminate inflorescence was observed. — Iso- 

 lated in 1907, this strain proved to be exceedingly variable in the number of plants which 

 bore ears with double grains. After five years of selection, the author reports that he has 

 fixed the strain to some extent. His data show approximately fifty per cent of plants with 

 double grains in 1919. At the same time the number of double grains on the ear has increased 

 from 5 per cent to 95 per cent.— The author calls this a typical case of a heritable, acquired 

 character. — E. W. Lindstrom. 



862. Blaringhem, L. Stabilite et fertilite de I'hybride Geum urbanum L. X G. rivale 

 L. [Stability and fertility of the hybrid, Geum urbanum L. X G. rivale L.] Compt. Rend. 

 Acad. Sci. Paris 170: 1284-1286. May, 1920. 



863. Bond, C. J. On certain factors concerned in the production .of eye colour in birds. 

 Jour. Genetics 9: 69-81. Dec, 1919.— Eye colors of birds are arranged in a series. At the 

 bottom is "bull" eye, as found in pigeons, which is due to absence of anterior pigment in iris 

 and background of black pigment in the uvea. Next stage is pearl eye of pigeons and "daw" 

 eye of fowls, caused by colorless granules in the iris, which destroy its translucency. In 

 extreme cases this type of eye may be china-white as in the "wall" eye of dogs, horses and 

 pigs. Yellow or "gravel" eyes are due to a network of branching cells crowded with small 

 spherical yellow granules on the anterior surface of the iris. Brown and black eyes are due 

 to brown or black pigment replacing or covering the yellow (giving triplex condition). The 

 ruby eye is produced by yellow pigment in conjunction with the red capillaries, except in the 

 Cayenne Lapwing, where actual reddish pigment granules are found. Some data on inherit- 

 ance of the types are given. In general they form an epistatic series, with the simplex "bull" 

 eye at the bottom. There are some complications due to secondary sex relations.— Leon /. 

 Cole. 



864. Bond, C. J. On the left-sided incidence of the supernumerary digit in heterodacty- 

 lous fowls. Jour. Genetics 10:87-91. July, 1920.— Author reports that among 38 hetero- 

 dactylous (five toes on one foot and four on the other) offspring from various crosses of four- 

 toed and five-toed breeds of fowls, 34 had the extra digit on the left side and only four on the 

 right side. Reports slight indication that this situation is more likely to prevail when the 

 female parent belongs to the five-toed breed. Data of other investigators are discussed 

 and the conclusion reached that in birds "there is a tendency during the early cleavage of 

 the ovum which separates the organism into a right and left half, for the factor or factors 

 which control meristic variation to pass to the left rather than to the right half of the devel- 

 oping zygote." — W. A. Lippincott. 



865. Boring, Edwin G. A priori use of the Gaussian-law. Science 52: 129-130. Aug. 6, 

 1920.— The author criticizes Mr. Michael's interpretation of Dr. Johnstone's results for 

 twenty counts of bacteria in polluted shell fish. He objects to Michael's factoring of a 

 skew distribution into a Gaussian distribution and a skewing factor on the ground that, in 

 absence of observational proof that the frequencies at hand follow the Gaussian law, this 



