No. 3, April, 1921] GENETICS . 251 



1742. Davenport, C. B. Annual report of the Director of the Department of Experi- 

 mental Evolution and of the Eugenics Record Office. Carnegie Inst. Washington Year Book 

 19. (1920): 107-157. 1921. — Surveying the past, author points out part played by his Staff 

 in helping to establish relation of chromosomes to genetical facts and as to future plans he 

 emphasizes the eugenical, and the desirability of much mammalian experimentation as likely 

 to bear strongest on human genetics. Metz reports on gametogenesis in Asiliis and Droso- 

 phila and finds indications in latter of process differing in male and female. A set of 3 allelo- 

 morphic mutations of the eye in D. virilis is mentioned, of which 2 are accompanied by more 

 or less sterility. MacDowell has completed a report showing that alcoholic grandparents 

 diminish learning and retention ability of rats. Alcoholic parents showed similar but less 

 marked influence on children, although latter were one generation nearer to the alcohol. 

 Riddle studied metabolism of male and female embryos in doves and pigeons. Relatively 

 more female than male embryos withstood diminished oxygen pressure, indicating lower 

 metabolism in females. Age of embryo is important factor in survival. Little demon- 

 strated presence of sex-linked lethal factors in mice causing ratio of sexes of about 1 male to 

 2 females. Statistical analysis of human pedigrees of hemophilia and color-blindness revealed 

 that considerably more than half of the males showed hemophilia or color-blindness and the 

 condition is thought to be due to lethal factors linked with normal allelomorphs of the abnor- 

 mal genes in sex chromosome. Proof of harmful action of weak acids on sperm was also 

 obtained. The previously known condition of heritability of cancer in mice was made much 

 more definite by Little whose F2 numbers point to 4 independent autosomal genes determining 

 susceptibility, all of which must be simultaneously present. Occurrence of spotted mutants 

 in non-spotted dog breeds is also recorded by Little. Banta reported that selection for sex- 

 intergradedness in Daphnids was successful. A report on selection for reactiveness to 

 light was completed. Banta was also interested in supposed mutative color changes in 

 flounders, 20 per cent of the new year's crop being pigmented on the lower side. Blakeslee 

 continued studies on mutation and sexuality in Mucors. In Portulaca a dominant vegetative 

 mutation affecting flower color appeared in a part of a white plant. Some cases like that of 

 a purple flower breeding white are deemed to have been periclinal chimeras. In Datura, 

 work on the graft-infectious disease "Quercina" has been completed. The mutant "New 

 Species" was found to be tetraploid, i.e., with 24 chromosomes. "Globe" type of mutant 

 seems to be due to 25 chromosomes. Harris with others has reported on vascular anatomy 

 of variant bean seedlings; on the physiology of egg production; on properties of vegetable 

 saps and on theory of plot tests. Banker's study of heredity in a human pedigree of better 

 sort revealed large number of college men. Some lines showed higher percentage than others. 

 Davenport studying twin births found that twinning is due to both father and mother. He 

 completed anthropological studies of American population based on army data. Laughlin 

 has completed a work on eugenical sterilization in the United States and collected data on 

 state institutions for defectives. — James P. Kelly. 



1743. Dorset, M. J. A note on the dropping of flowers in the potato. Jour. Heredity 10: 

 226-228. Fig. 19. 1919. — On most of the common varieties of potatoes many of the flowers 

 absciss either before the flower opens or before fertilization can take place. In some cases 

 the partially developed seed ball will absciss. Since pollen abortion is very common and 

 occurs in varying percentages, though the flowers develop perfect pistils, and since abscission 

 occurs before tuber formation or the stimulus due to fertilization, it is evident that some 

 other physiological process is active. — •/. H. Beaumont. 



1744. Ellinger, Tage. On the numerical expression of the degree of inbreeding and 

 relationship in a pedigree. Amer. Nat. 54: 540-545. 1 fig. Nov. -Dec, 1920.— The paper 

 gives a modification and some extensions to the system of measuring degrees of inbreed- 

 ing and relationship published by Dr. Raymond Pearl in several articles in the American 

 Naturalist, 1913-1917. — 'It is attempted first to bring all measurements on the same scale and 

 for that purpose it has been necessary slightly to change the definition of the Coefficient of 

 Relationship, and further to express both the Total Inbreeding Coefficient and the new Total 



