878 EXPERIMENT STATION RECOBD. 



the character of the part it was destined to become. No regeneration of the 

 limbs toolc phice after removal of the buds. 



Light thrown by the experimental study of heredity upon the factors and 

 methods of evolution, C, B. Davenport (Amcr. Nat., J/d. (1912), No. 5^3, pp. 

 129-138). — The new views of looking at problems of heredity and the origin of 

 differential characters of organisms are discussed. One cause of sterility in 

 rumpless fowls is explained. 



Problems of evolution and present methods of attacking them, E. G. 

 CONKLIN (Anier. Nat., 46 (1912), No. 5f,3, pp. 121-128).— A discussion of the 

 merits of the experimental method, and the possible causes of the origin of new 

 characters. It is pointed out that it has not yet been proved that the determina- 

 tion of unit characters is beyond the reach of environmental influences. 



Further remarks on the law of ancestral heredity, K. Pearson (Biometrika, 

 8 (1911), No. 1-2, pp. 239-243).— The applications of this law are illustrated 

 by mathematical formulas. It is pointed out that the theory of multiple cor- 

 relations is the natural one in which to approach the theory of ancestral inheri- 

 tance, and that there is uo regression whatever on Galtou's hypothesis after the 

 first generation, at which selection is stopped. 



Biotypes and phylogeny, H. L. Clark (Amer. Nat., 46. (1912), No. 543, pp. 

 139-150). — A discussion of the relation of pure strains (biotypes) to the phylo- 

 genetic problems which concern the systematist. 



An alleged specific instance of the transmission of acquired characters. — 

 Investigation and criticism, T. G. Brown (Proc. Roy. Soc. [London], Ser. li, 

 84 (1912), No. B 575, pp. 555-579, figs. 3).— A report of experiments in pro- 

 ducing the Brown-Sequard phenomenon in guinea pigs. 



The author finds that the phenomenon is not an acquired peculiarity produced 

 de novo on division of the great sciatic nerve, but is due to the raised excita- 

 bility of a mechanism already present when the inhibiting influence is removed 

 by sectioning the nerve. The phenomenon, therefore, can not be considered 

 as transmissible as an acquirement per se. If anything is transmitted as an 

 acquired character it must be the state of raised excitability of the scratch- 

 reflex. 



The presence of the phenomenon may be admitted, but this may be explained 

 as due to a production of the state by injury to the toes and feet inflicted by 

 the parent, and is therefore not a case of transmission of acquired char- 

 acteristics. 



On the origin of a pink-eyed guinea pig with colored coat, W. E. Castle 

 (Science, n. ser., 35 (1912), No. 900, pp. 508-510).— In the course of an attempt 

 to reduce the amount of pigment by systematic selection the author has obtained 

 a guinea pig closely resembling an albino, but with spots of blue on the right 

 side of its head and on the hips. Apparently it represents a long step in the 

 modiflcation of a race by artificial selection, in which the color factor or factors 

 become so modified as to give an extreme case of dilution. 



Another case of sex-limited heredity in poultry, C. B. Davenport (Proc. 

 Soc. Expt. Biol, and Med., 9 (1911), No. 2, pp. 19, 20).— In reciprocal crosses of 

 dark Brahmas and brown Leghorns the males were white-laced, but the wing 

 bar was red in the male offspring. This was not the case with the pullets, as 

 they always inherited the lacing of the male parent. The hybrids have been 

 bred together and produced a second generation. When a hybrid male was 

 mated to a white-laced hybrid female all the offspring were white-laced, while 

 half the pullets were white-laced and half red-laced. With the reciprocal cross, 

 half of the male offspring were white-laced and half red-laced, while half of 

 the pullets were white-laced and half red-laced, as iu the reciprocal mating. 



