772 KXPERIMENT STATION KKCORD. 



566-571). — Where a number of indlviduala in au array is small the method 

 outliued is of no very marked advantage, but when the arrays are large it 

 saves much labor and has a wide range of application. 



Experimental polyspermy as a means of studying the problem of fecunda- 

 tion, A. Hkachkt (Arch. IJiitwivkl. Mcrh. Onjan., ,W HDIO). pt. 1. pi>. 2GI-303, 

 figs. 9; aha. in Zenthl. Phi/sioL, >!, (I'Jll), No. 23, p. lOflJ,).— The author has 

 studied fecundation under abnormal conditions in liana fusca for the purpose of 

 gaining Information on the underlying principles. When the sperm was concen- 

 trated many spermatozoa could enter the ovum, and if the number entering 

 was small there were as many blastomeres as there were sj)ermatozoa. The 

 female nucleus united with the spermatozoa lying nearest to it. When the 

 number of spermatozoa was large there was more or less union among them, 

 forming groups and cliaius. 



Results obtained thus far furnish further support to the view that the 

 phenomenon of fecundation may be accounted for by forces lying entirely within 

 the nucleus. 



Artificial parthenog-enesis of frog's eggs, E. Bataillon ( Compt. Rend. Acad. 

 Set. [Paris], 150 (1910), No. 16, pp. 996-998; 152 (1911), No. 19, pp. 1271- 

 1273; abs. in Jour. Roy. Micros. Soc. [London], 1910, No. 6, p. 706; 1911, No. 4, 

 p. 'i5Jf). — A minute puncture of the eggs of Rana fusca with a fine needle made 

 of glass, platinum, or manganese apparently caused a change in the osmotic 

 oquilibrimn, as many eggs underwent gastrulation and developed into free 

 larvae. Segmentation was also induced by injecting into the eggs some mam- 

 malian blood, sperms, extract of spleen, carp blood, or extract of testis. The 

 accelerating principle introduced need not be specific. The essential conditions 

 are puncture and the introduction of some foreign cellular elements. 



Number of chromosomes in Batrachians and in parthenogenetic embryos, 

 A. Dehorne (Compt. Rend. Acad. Set. [Paris], loO (1910), No. 22, pp. l.',51- 

 V,53; 152 (1911), No. 17, pp. 1123, 1124; ais. in Jour. Roy. Micros. Soc. [Lon- 

 don], 1910, No. 6, p. 706; 1911, No. 4, p. 4J//).— The exi^riments of Bataillon 

 (noted above) were repeated and only 6 chromosomes were found in the cells of 

 embryos from 2 to 6^ days old. The author finds that all the common Batra- 

 chians have 12 chromosomes, and not 24 as usually stated. 



Studies in experimental enabryology. — Effect of radium on the egg of the 

 fowl, G. Vebnoni (Arch. Enticickl. Mcch. Organ., 31 {1910), pt. 2, pp. 307-S34, 

 pis. 3). — A detailed report of a study of the changes, both progressive and 

 regressive, brought about by the action of radium on the development of the 

 egg. A review of previous work by other investigators is included. 



The state of the ovary in hybrids of the goldfinch and canary, A. Chapel- 

 UEB (Compt. Rend. Soc. Biol. [Paris], 70 (1911), No. 9, pp. 328, 329, figs. 8; abs. 

 in Jour. Roy. Micros. Soc. [London.], 1911, No. 4, V- 455). — The author examined 

 25 hybrids between a male goldfinch and female canary, finding various degrees 

 of fertility. In some cases the ovary was rudimentary and no ova were pro- 

 duced. In others, the eggs were small and sterile. Eggs were laid in only 

 about one-fourth of the cases. 



Studies in the experimental analysis of sex. — VI, On the cause of the 

 fluctuations in growth of the fowl's comb, G. Smith (Quart. Jour. Micros. Sci. 

 [London], n. ser., 57 (1911), No. 225, pp. 45-51, pis. 4, fiffs. 5). — The results of 

 this investigation, continuing previous studies (E, S. R., 23, j), 173), are sum- 

 marized as follows : 



" The rapid and marked increase in area of the hen's comb is proved both in 

 adult and young hens to occur simultaneously with the periods of egg laying. 

 This increase of the comb In the hen is due to a fatty infiltration of the central 

 connective-tissue core of the comb : the decrease in the comb is due to thQ 



