472 EXPERIMENT STATION EECORD. 



" The entire fresh egg has a slight but definite catalytic power which remains 

 practically constant even though the egg be kept for several months at room 

 temperature. The separate parts of the egg, germinal center, yolk, and white 

 have practically no activity when tested individually. The entire unfertilized 

 egg shows no catalytic activity even after incubation at 38° for 21 days. 

 The germinal portion of the incubated fertilized egg rapidly acquires the 

 power of decomposing hydrogen peroxid, while the yolk and white together 

 or separately show no such increase, nor is there any activity to be found in 

 the amniotic fluid. It seems, therefore, that the catalytic power of the develop- 

 ing egg is formed from the contents of the egg which themselves show little 

 action, by the developing germinal portion, independent of all external influ- 

 ences except heat (38°) and air." 



Ovulation in mammals, with special reference to the mouse and rat, W. B. 

 KiKKHAM (Biol. Bui. Mar. Biol. Lab. Woods Hole, IS {1910), No. 5, pp. 2^5- 

 251). — Following a review of investigations on ovulation in connection with 

 pairing in sheep, swine, dogs, and small mammals in which the results seemed 

 to be conflicting as to whether or not ovulation is dependent upon pairing, the 

 author reports recent experiments of his own made in order to test this point. 

 He found that ovulation took j)lace in virgin white mice and in adult white 

 rats without pairing. It is suggested that the mouse is a suitable mammal 

 upon which to investigate the pcjssibility of artificial parthenogenesis. 



Methods of artificial parthenogenesis, E. N. Harvey (Biol. Bui. Mar. Biol. 

 Lai). Woods Hole, IS (1910). Xo. .5, pp. 269-2 SO) .—This is a list of important 

 contributions giving briefly the various methods of exciting eggs to develop, 

 together with results and references, in the hope that it may prove of value to 

 future AAorkers. 



Studies on the determination of the female sex, A. Russo (Studien iiher die 

 Besti)iiinitiuj dcs KciljlicJun Geschlechtcs. Jeua. 1909, pp. 105, figs. 32). — This 

 contains an account of the histology and physiology of the ovarian tissues, 

 and reports investigations which have been previously noted from another 

 source (E. S. R., 21, p. 269). 



Russo on sex determination and artificial modification of the Mendelian 

 ratios, W. E. Castle {Amer. Nat., U (1910), No. 523, pp. 1,34^^39). —The work 

 of Russo, noted above, is criticised on two grounds: First, that Russo's claim 

 that the female sex can be produced artificially by injections of lecithin is 

 vitiated by the fact that he reported only selected experiments which were 

 favorable to his theory; second, that his results might be interpreted differ- 

 ently if the gametic constitution of the breeding stock were known. 



Experimental studies on somatic and sexual differences, I, J. Meisen- 

 HEiMER (Experimentelle Studien zur Soma- tind Oesehlechts-Differenzierting. 

 Jena, 1909, pp. VII+J.'j9; rev. in Nature [London^, 83 (1910), No. 2116, pp. 335, 

 336; Amer. Nat., U (1910), No. 521, pp. 316-319).— By means of an electric 

 needle and knife the sexual glands, anlage of accessory genital apparatus, and 

 anlage of wings were removed from all six larval stages of the moth Lymantria 

 dispar and the sexual glands of the opposite sex were transplanted. Another 

 series of experiments were also tried on Oryyia gonostigma. 



From these experiments the author concludes that in these moths the primary 

 sex cells have no influence on secondary sex characters. This does not lend 

 support to the theory that internal secretions from the sex glands affect the 

 soma, as both primary and secondary sexual characters are inherited directly 

 from the young germ cells. 



The influence of the cortical centers on the sexual organs, C. Ceni (Arch. 

 Ital. liioh. ',S (1907). No. 3. pp. 'i9-66. figs. If; Ric. Spcr. Fren., 35 (1909); 

 abs. in Arch. Rasscn u. Gescll. Biol., 7 (1910), No. 2, pp. 2J,S, 2J,9).—The niuti- 



