52 GENETICS [BoT. Absts., Vol. VIII, 



331. ScHiEMANN, E. Zur Frage der Briichigkeit der Gerste — eine Berichtigung. [On the 

 question of brittleness in barley — a correction.] Zeitschr. Indukt. Abstamm.- u. Vererb. 21 : 53. 

 1919. — A correction of a misstatement in an earlier paper, due to a typographical error, and a 

 reply to a criticism of the author's interpretation of the inheritance of brittleness of rachis in 

 barley crosses. — C. B. Hutchinson. 



332. Schmidt, JoHS. IV. The genetic behaviour of a secondary sexual character. Compt. 

 Rend. Trav. Lab. Carlsberg 14: 1-12. 6 pi. 1920. 



333. ScHRADER, Franz. Peculiar chromosomal phenomena in a Homopteran. [Abstract.] 

 Anat. Rec. 20: 200-201. 1921. — In Pseudococcus nipae, a Homopteran, both sexes have a 

 diploid number of 10 chromosomes. In the female, 5 tetrads are formed and reduction results 

 in the haploid number of 5 chromosomes as in the ordinary manner. In the male, the growth 

 stages of the spermatocytes show 5 of the 10 chromosomes condensing in advance of the 

 remaining chromosomes. These 5 chromosomes can be identified in following stages by the 

 tendency to remain in a more or less clumped group. No trace of tetrad formation could be 

 found. The 1st spermatocyte division is equatorial and 10 chromosomes go to each pole. The 

 2nd division is reductional and this apparently takes place in that the 5 clumped chromosomes 

 go to one, and the remaining 5 to the opposite pole. Early spermatids still show 5 chromo- 

 somes and the formation of spermatozoa seems to follow ordinary lines. — Franz Schrader. 



334. ScHULTZ, Walther. Kalteschwarzung eines Saugetieres und ihre allgemeinbio- 

 logischen Hinweise. [Darkening of a mammal by cold and its general biological significance.] 

 Arch. Entwicklungsmech. 47:43-75. 12 fig. 1920. 



335. SiRKS, M. J. [Dutch rev. of: Golds chmidt, R. Der Mendelismus in elementarer 

 Darstellung. [Elementary presentation of Mendelism.j 77 p., 15 fig. P. Parey: Berlin, 1920.] 

 Genetica 2: 532-533. 1920. 



336. SiRKS, M. J. [Dutch rev. of: Golds chmidt, R. Einfiihrung in die Vererbungswis- 

 senschaft. Zwanzig Vorlesungen fiir Studierende, Aerzte, Ziichter. Dritte neubearbeitete Auf- 

 lage. [Introduction to the science of genetics. 20 lectures for students, physicians, breeders.) 

 Srd revised ed., 519 p., 178 fig. W. Engelmann: Leipzig, 1920.] Genetica 2: 533-534. 1920. 



337. SiRKs, M. J. [Dutch rev. of: Heribert-Nilsson, Nils. Ein tJbergang aus dem 

 isogamen in den heterogamen Zustand in einer Sippe der Oenothera Lamarckiana. (A transi- 

 tion of the isogamic to the heterogamic condition in a strain of Oenothera Lamarckiana.) Hered- 

 itas 1 : 213-220. 1920.] Genetica 2 : 545-546. 1920. 



338. SiBKs, M. J. [Dutch rev. of: Malinowski, Edmund. Die Sterilitat der Bastarde 

 im Lichte des Mendelismus. (The sterility of hybrids in the light of Mendelism.) Zeitschr. 

 Indukt. Abstamm.- u. Vererb. 22: 225-235. 1920.] Genetica 2 : 540-542. 1920. 



339. Skupienski, F.-X. Sur la sexualite chez une espece de M3ncomycete Acrasiee 

 Dictyostelium mucoroides. [On sexuality in a species of Acrasiae Dictyostelium mucoroides.] 

 Compt. Rend. Acad. Sci. Paris 167: 960-962. 1918. 



340. Steinach, E. Verjxingung durch experimentelle Neubelebung der alternden Puber- 

 tatsdriise. [Rejuvenation through experimental revitalization of the senile sex glands.] Arch. 

 Entwicklungsmech. 46: 557-619. 9 pi., 7 fig. 1920. — By the use of two methods, viz., section 

 of the vas deferens and transplantation of gonads, Steinach has brought about rejuvenes- 

 cence in senile rats. Great care was used to make sure that the rats were really senile before 

 each experiment was begun. Histological examinations of the testes were made. After sec- 

 tion of the vasa deferentia, a multiplication of Leydig's cells took place, accompanied by a 

 return to the normal vigorous condition of rats in the prime of life. The span of life of these 

 rats exceeded the normal by about 25 per cent. A rejuvenescence also was observed in 3 old 

 men on whom similar operations were performed. Transplantation of testes and ovaries gave 

 like results.— ff. D. Goodale. 



