140 GENETICS [Box. Absts., Vol. VII, 



larger cows were more economical producers than the smaller cows. The Holsteins of the 

 heaviest class produced 29.2 pounds more milk for each 100 feed-units than did the Holsteins 

 of the lightest class, while the largest Guernseys produced 20.5 pounds more milk than the 

 lightest class, and the heaviest-class Jerseys produced 21 pounds more milk per 100 feed- 

 units consumed than the lightest class. The larger animals are also shown to be more eco- 

 nomical producers of total solids and butter-fat than the smaller animals. — The Holsteins 

 in this contest were the most efficient producers of milk and total solids, while the Guernseys 

 and Jerseys were the most efficient producers of butter-fat. — R. R. Graves. 



923. Onslow, H. Inheritance of wing colour in Lepidoptera IV. Melanism in Boarnia 

 abietaria. Jour. Genetics 10: 135-140. / pi. Aug., 1920. — Inheritance of melanism was 

 previously described by author in related species, — Tephrosia consonaria and Bosnaria con- 

 sortaria. These three species are confined to Kent and Surrey (with another melanic variety 

 Tephrosia extensaria (luridata)). [Onslow, Jour, of Genetics, 9: 53, 339. Dec. 1919, Mar. 

 1920.] In melanic form has wings of female uniform velvety black, of male, slightly browner, 

 distal streak and veins traced in deeper black, otherwise unmarked. Type strain varies in 

 color and markings from very dark to golden brown. Females slightly darker than males. — 

 Character of matings made: Melanic X melanic, where one parent at least was homozygous 

 (DD X DD (DR) ; melanic X melanic where both parents were heterozygotes (DR X DR) ; 

 melanic X type where melanic parent was homozygous (DD X RR); melanic X type 

 where melanic parent was heterozygous (DR X RR). In each of these crosses the melanic 

 parent behaves as a simple Mendelian dominant to type forms. In a certain brood from 

 melanic X type, the male parent being comparatively very light, light offspring and melanics 

 appeared in equal numbers as expected, the light offspring appearing lighter than in other 

 strains but not so light as male parent. — Results in agreement with conclusions of Bowers 

 ^Ent. Rec. 11: 82, 1899), and Stallman (Ent. Rec. 28: 21, 1916) in experimental breeding of 

 melanics. — Isabel McCracken. 



924. [Pearson, Karl.] Peccavimus. Biometrika 12: 259-281. Nov., 1919.— This paper 

 cites certain errors which have crept into publications of biometrical formulae. The cor- 

 rections are indicated. — John W. Gowen. . 



925. Pennypacker, J. Y. Observations on the beach plum. A study in plant variation. 

 Contrib. Bot. Lab. Univ. Pennsylvania 4: 231-270. PI. 66-70. 1920.— Author is impressed 

 with marked variation in the beach plum {Prunus maritima) and suggests that this species is 

 undergoing mutational variation along several lines due to environmental factors. Primi- 

 tive color is supposed to have been greenish yellow or red. Through transformation of 

 chloroplastids to chromoplastids pure yellow fruits arose along one evolutionary line. 

 Development of purple and then blue considered another line. Reference is made to Bur- 

 bank's hybridization work with P. maritima. Detailed description is given of nine varie- 

 ties of the species of interest especially to taxonomists. — James P. Kelly. 



926. Pridham, J. T. Breeding cereals at the experiment farms. Agric. Gaz. New South 

 Wales 31: 697-698. 1920. — Summary is given of plant-breeding work and nursery trials at 

 several of the experimental farms. — L. R. Waldro7i. 



927. PuNNETT, R. C. The early elimination of surplus cockerels. Jour. Bd. Agric, 

 London 25: 1319-1323. 1 fig. 1919.— Author shows how appropriate crosses of races of 

 poultry, involving sex-linked factors which manifest themselves in the down, make it 

 possible to distinguish the sex of the offspring at hatching. Suggests possible practical 

 applications. — William A. Lippincott. 



928. Richardson, C. W. Some notes on Fragaria. Jour. Genetics 10:39-46. 2 fig. 

 July, 1920. The work is a continuation of that published in the same Journal 3 : No. 3, 1914, 

 and 7: No. 3, 1918. [See Bot. Absts. 2, Entry 494.] The results of certain crosses are given 

 with regard to the inheritance of flower color, double flowering, shape of foliage, variegation in 



