160 GENETICS [Bot. Absts., Vol. VI, 



1116. Roffo, A. H. Sur le role du facteur race dans la transmission du cancer chez le rat. 

 Transformation progressive d'une race non receptive. [On the role of the race factor in the trans- 

 mission of cancer in the rat. Progressive transformation of a non-receptive race into a recep- 

 tive one.] Compt. Rend. Soc. Biol. 83: 968-970. 1920— See Bot. Absts. 6, Entry 1749. 



1117. Saint-Hilaire, H. Geoffroy. L'elevage dans l'Afrique du Nord. [The breeding 

 industry in North Africa.] xi + 530 p., 33 pi. Augustin Challamel: Paris, 1919. 



1118. Schade, H. J. M. Kunnen proefondervindelnke mutaties worden opgewekt bij 

 bacterien? [Can experimental mutations be obtained in bacteria?] Nederlandsch. Tijdschr. 

 voor Geneeskunde 63: 811-814. 1919. — The researches of Seiffert (Deutsche medizinische 

 Wochenschrift 1911. no. 23) and of Richet and Cardot (C. R. Acad. Sciences, Paris, 31 March, 

 1919) have been repeated by the author. Their conclusions accepted the possibility of obtain- 

 ing mutations, by means of bacterial cultures in special media. Author made his cultures, as 

 Seiffert had done, of B. coli in agar, to which malachite-green had been added; from the 

 original culture, that could be only grown in agar-nurture with 20 mg. in 10 cc. agar, a strain 

 was cultivated, that was resistant to 666 mg. in the same quantity of agar; after three 

 months this resistance was not diminished. The conclusion of Seiffert and others seemed 

 to be right. That this is not true, however, is shown by the author in a way, different 

 from his previous method. By means of emulsions of his cultures in NaCl-solution, colonies 

 were obtained from very diluted cultures; the strain "adapted" to 666 mg. of malachite per 

 10 cc. agar grew on each culture as well; this "mutated" strain, after once growing upon 

 pure agar, had lost its adaptation for the greater part; the longer the period of growing upon 

 pure agar, the less the adaptation and the number of resulting colonies. In his first men- 

 tioned researches, common cultures did not bring these differences to light because of the 

 immense number of bacteria contained in only one little globule of the culture; after diluting 

 the cultures by means of emulsions, the differences made themselves apparent. Thus the 

 conclusions of Seiffert and of Richet and Cardot are false because of their inexact 

 methods. — M. J. Sirks. 



1119. Schermers, D. Erfelijkheid en rasverbetering. [Heredity and race-improvement.] 

 Schild en Pijl 10: 1-26. 1919. — From the point of view of positive Christianity the writer dis- 

 cusses the consequences, drawn by the modern eugenicists from the facts given by processes 

 of fertilization and of Mendelism. He is extraordinarily skeptical. The great and insuper- 

 able difficulties, encountered by the study of heredity in man, especially as related to psychi- 

 cal abnormalities, leads him to deny the practical significance of eugenics; medical examina- 

 tion before marriage can only give good results for alcoholism, syphilis and tuberculosis; in 

 other cases it will be wholly insufficient, while neomalthusianism is fatal. The prospects of 

 a possible improvement of the human race are, owing to the lack of well-established knowledge, 

 unfavorable. — M. J. Sirks. 



1120. Siegel, W. Das Recht des Gemiiseziichters. [The right of the vegetable breeder.] 

 8vo. Frick : Wien, 1919. — Author takes up the well-known idea of according to breeders work- 

 ing with cross-pollinated vegetables protection from neighboring cultures of the same species. 

 [From anonymous review' in Zeitschr. Pflanzenziicht. 7: 146. Dec, 1919.] — J. P. Kelly. 



1121. Sirks, M. J. De analyse van een spontane boonenhybride. [The analysis of a spon- 

 taneous bean hybrid.] Genetica 2: 97-114. Mar., 1920. — Among a number of plants of the 

 dwarf speckled cranberry bean, gathered in 1917, one plant was found whose seeds had not a 

 chamois (yellowish-white) violet-striped seedcoat, but a liver-brown one with blue striping. 

 These seeds had thus been formed on a hybrid plant, resulting from a crossing with an unknown 

 pollen parent, occurring in 1916. By sowing these seeds in 1918, an F 2 -generation was obtained 

 and in 1919 an regeneration. The analysis of these F> and F 3 generations with regard to their 

 seed colors, gave cause to accept seven hereditary factors, present in beans and responsible 

 for these colors. These factors were: — (1) The ground-factor, P, responsible for color in 

 general; its presence without others causes the chamois color, its absence gives a white seed- 



