Experimental Evolution, Variation, and Heredity 99 



No. 101. (Paper No. 11, Station for Experimental Evolution.) 

 LUTZ, FRANK E. The Variation and Correlation of the Taxonomic Characters of 

 Gryllus. Octavo, 63 pages, 6 figures. Published 1908. Price $0.40. 



A critical, biometric study of the species of the genus Gryllus, or crickets. In 

 the genus all characters are highly variable; some, like ovipositor length, seem 

 affected by local influences. Wing length is dimorphic and the two forms fail to 

 intergrade. This character is studied in detail. General conclusions are drawn as 

 to evolution and the species question. 



No. 112. (Paper No. 12, Station for Experimental Evolution.) 

 SHULL, G. H. Bursa bursa-pastoris and Bursa heegeri: Biotypes and Hybrids. 

 Octavo, 57 pages, 4 plates, 23 text figures. Published 1909. Price $0.50. 



Of the common shepherd's purse only a single species is usually recognized; 

 yet a casual acquaintance with the species shows that it is very variable. The 

 leaves of the rosette, particularly, show many characters, of which four as least are 

 inherited in typical fashion. One kind of leaf has attenuated lobes with a basal 

 secondary lobe; another attenuated lobes without the basal one; a third has a 

 short lobe with a secondary one; the fourth has the lobe both short and without 

 a secondary one. Hybridization proves that the two conditions of both primary 

 and secondary lobing are inherited as distinct characters, but the statistical results 

 are often blurred by the imperfection of dominance. Bursa heegeri is a rare 

 species, thought to have arisen from bursa-pastoris by a mutation which has re- 

 sulted in an elliptical instead of a triangular seed capsule. When hybridized with 

 bursa-pastoris, segregation of capsule-form occurs, but the proportion of elliptical 

 capsules in the second hybrid generation is only 4 per cent instead of 25 per cent. 

 Additional factors are suspected or else there is selective fertilization or survival. 



No. 114. (Paper No. 13, Station for Experimental Evolution,) 

 CASTLE, W. E., in collaboration with H. E. WALTER, R. C. MULLENIX, and S. COBB. 

 Studies of Inheritance in Rabbits. Octavo, 70 pages, 4 plates. Pub- 

 lished 1909. Price $0.75. 



This is a continuation of the series of studies upon heredity in mammals of 

 which earlier numbers are Nos. 23, 49, and 70, of the publications of the Carnegie 

 Institution of Washington. Heredity of ear-size in short vs. lop-eared rabbits is 

 first considered. The normal rate of growth is described for both varieties and also 

 the result of pure breeding and cross-breeding. The conclusion is reached that the 

 cross-breeds are not only blends but the blend is permanent. Part II deals with 

 body-weight and the conclusion is reached that weight inheritance like the inheri- 

 tance of ear-size is blending in character. Neither dominance nor segregation ia 

 the mendelian sense is recognizable. Part III is concerned with skeletal dimen- 

 sions which also prove to be blending characters. In Part IV, 24 pages are given 

 to an analysis of color factors in the coat of the rabbit. This analysis is carried 

 further than hitherto in any group of animals. 



No. 121. (Paper No. 14, Station for Experimental Evolution.) 

 DAVENPORT, C. B. Inheritance of Characteristics in Domestic Fowl. Quarto, 100 

 pages, 12 colored plates. Published 1909. Price $4.50. 



In the newer studies of heredity attention is directed to the characteristics of 

 organisms taken one at a time. Great diversity in the method of inheritance is 

 found. The present work considers behavior of ten morphological characters and 

 the principal colors of poultry. Some characters are evidently simple and are 

 inherited in accordance with the pure Mendelian formula; others show marked de- 

 viations from it such as "blending" and imperfect dominance. Even in such cases, 

 however, a segregation of characters takes place in the germ-plasm. The characters 

 analyzed in detail are the split or Y comb, polydactylism, syndactylism, rumpless- 

 ness, winglessness, booting, nostril, crest, and comb-lop. The inheritance of plum- 

 age color is described, and it appears that in each color-race the plumage coloration 

 is determined by a number of factors, the varied combinations of which account for 

 "reversion,' "sporting," and various apparent abnormalities in the reproduction of 



