1920] ANIMAL PRODUCTION. 67 



colored drawings, constitute the record of 18 years' investigations of evolu- 

 tion, lieredity, and betiavior in pigeons. Forty-three species of wild pigeons 

 collected in various parts of the world were bred In captivity and kept under 

 observation to study their color patterns at different ages and their repro- 

 ductive instincts. Many were crossed with other species and with domestic 

 pigeons. At the time of Whitman's death in 1910 the work was still in active 

 progress, and only a small fraction of the material in these volumes was in 

 manuscript form. To Riddle fell the task of bringing to a conclusion such of 

 the breeding operations as were well under way and of preparing for publica- 

 tion an account of the work based on Whitman's MSS., notebooks, and I)reed- 

 ing records. Later the editorial treatment of the behavior studies (grouped 

 to form vol. 3) was allotted to Carr. The title and an outline of the contents 

 of each volume follow : 



Orthogeiietic evolution in pigeons (vol. 1). — Matters discussed include the 

 origin and relationship of rock-pigeons as revealed by their color patterns, the 

 turtle-dove pattern in the phylogeny of pigeons and in other orders of birds, 

 frills and fundamental bars as plumage characters in pigeons (with notes on 

 similar conditions in domestic fowls and geese), color mutations in pigeons, 

 and several general topics dealing with the problem of organic evolution. The 

 turtle-dove pattern (feathers with dark centers and light margins) is con- 

 sidered the primitive type in pigeons, and other patterns including the wild 

 rock are held to have developed from this type by an orderly process of evolu- 

 tion in a definite direction. 



Inhciitance, fertility and the dominance of sex and color in hybrids of tiHld 

 species of pigeons (vol. 2). — This volume is chiefly a record of experimental 

 crosses. Most of the crosses were between different wild species or genera, be- 

 cause Whitman deemed purity of the original stock essential for inheritance 

 investigations. As a consequence, the studies could not in general be continued 

 beyond the first generation, owing to the sterility of hybrids. 



Of the 17 chapters, only .5 are from Whitman's pen directly, viz, an intro- 

 ductory chapter on species hybrids in pigeons, and papers entitled Ses-llmlted 

 Heredity in Crosses involving Blond and White Ring-doves and Related Species ; 

 on the Nature and Basis of Heredity ; Influence of the Spermatozoa of Pigeons 

 on Rate of Development of Embryo ; and On the Divisibility of Characters. « The* 

 remaining chapters are detailed accounts by Riddle of the colors, .sex, and fer- 

 tility of the hybrids, based mainly on data tabulated by Whitman. The view- 

 point with regard to sex determination and its relation to season, reproductive 

 overwork and width of cross is the same as that expounded by Riddle in a num- 

 ber of previous papers, some of which have been noted (E. S. R., 33, p. 272; 35, 

 p. 771 ; 37, p. 868 ; 39, p. 575) . 



The behavior of pigeons (vol. 3). — This volume consists of a detailed study 

 of the mating instinct and reproductive cycle in pigeons, with briefer chapters 

 on the voice, the homing Instinct, and other instincts. 



On the possibility of intranuclear transfer in homozygotes, J. P. Lotsy 

 {Genetica [The Hague], 1 {1919), No. 1, pp. 92-97, figs. 10).— A theoretical dis- 

 cussion of the possibility of mutations originating by the transfer of chromatin 

 segments from one chromosome to a nonhomologous chromosome. 



Problems of animal breeding, J. A. S. Watson {Scot. Jour. Agr., 2 {1919), 

 No. If, pp. 449-456). — A popular discussion, calling attention particularly to the 

 undue amount of cattle crossing in Scotland and to the absurdity of the "family 

 craze" in evaluating Shorthorn and Angus pedigrees.' 



The effect of feeding pars tuberalis and pars anterior proprior of bovine 

 pituitary glands upon the early development of the white rat, C. J. 

 Mabinus (Amer. Jour. Physiol, 49 {1919), No. 2, pp. 238-247).— A group of 53 



