Vererbung, Variation, Mutation. 259 



812) Kelly, J. P., Heredity in a parthenogenetic insect. In: Amer. Na- 

 tural, Bd. 47, S. 229—234, 1913. 



A2}Ms rumicis, which is common on poppies and nasturtiums, was used for 

 study. The character studied was the ratio of the third antennal Joint to the 

 fourth. From the results, which are incomplete, it is concluded that somatic dif- 

 ferences within the parthenogenetic line are not inherited. Gates (London). 



813) Doiicaster, L. (Cambridge, University), On an inherited tendency to 

 produce purely female families in Ahraxas grossulariata, and its 

 relation to an abnormal chromosome number. In: Journal of Genetics, 

 Bd. III, Nr. 1, S. 1—10, 1913. 



Families consisting only of females appeared in six successive generations 

 of the moth Äbraxas grossulariata, but not every female of a unisexual family has 

 only female offspring. In some cases unisexual families have been produced from 

 parents belonging to bisexual families, but directly descended from unisexual. 

 Broods have also appeared with an enormous preponderance of females, but a 

 few males. The normal diploid number of chromosomes, in both sexes, is 56, 

 but females of the unisexual families have 55. Females belonging to bisexual 

 families, directly descended from unisexual, may have either 55 or 56 chromo- 

 somes. Males appear always to have 56. Doncaster (Cambridge). 



814) Goodale, H. D., Castration in relation to the secondary sexual 

 characters of brown leghorns. In: Amer. Natural., Bd. 47; S. 159 — 169, 

 1913. 



The adult plumage of Brown Leghorns is strongly sexually dimorphic and 

 is practically identical with that of the jungle fowl. The method of experiment 

 was to remove the gonads from young chicks 3 or 4 weeks old. It was found 

 that castration of the males did not result in the development of female charac- 

 ters, though such birds diff ered from normal males in the absence of sex instincts, 

 less activity, and a less-developed comb. Castration of females resulted in the 

 development of male characters, though the assumption of male characters is not 

 complete. It is concluded that the male is duplex for an internal secretion, S, 

 from the testes, which is necessary for füll development of comb and the croM^- 

 ing and sex instincts but not for the plumage and spurs. The formula for the male 

 is then supposed to be Sc? Sc?, and that for the female ScTS'? where S' is the 

 secretion from the ovaries. Gates (London). 



815) Geoffrey, Smith (Oxford, University) and Haig, Thomas, On sterile 

 and hybrid Pheasants. In: Journal of Genetics, Bd. III, Nr. 1, S. 39 — 52, 

 1 plate, 1913. 



Hybrid males of the crosses Reeves Pheasant JXFormosan cf, and Reeves 

 $ X versicolor S were found to have abnormal spermatozoa, due to the failure 

 of synapsis in the spermatocytes. Hybrid females of the same crosses had vesti- 

 gial ovaries, with no oocytes. Since the synapsis in birds occurs in the embryo,. 

 the failure to produce ova is doubtless due to the same cause which produces 

 sterility in the male. Sterile females, both in the hybrids mentioned and in the 

 common pheasant produce to a greater or less extent plumage resembling that 

 of the male. In some cases the oviduct was found to be vestigial, in others 

 hypertrophied, but it is clear that the assumption of male characteristics in the 

 plumage is connected with the vestigial condition of the ovary. In the rarer 

 cases of a male having to some extent the female plumage, the testes do not 



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