Vererbung, Variation, Mutation. 77 



miliar with 0. grandiflora as grown under a variety of conditions, a typical race 

 of 0. gramlitlora, and deVries was doubtless correct in so considering it. 



Gates (London). 



202) Davis, B. M., Mutations in OenotJiera hiennis L. In: Amer. Natural., ßd. 47, S. 116 

 —121, 1913. 



Remarks on a recent paper by Stomps. Gates (London). 



203^ Shaw, J. K., The effect of fertilizers on Variation in corn and beans. 

 In: Amer. Natural, Bd. 47, S. 57—64, 191;;. 

 The addition of various mineral fertilizers to corn crops did not, in most cases, in- 

 crease the stature of the plants, though nitrates had such an efliect. Combined with phos- 

 phates or potash the effect was more i^ronounced, and still greater when all three were 

 applied together. The Standard deviation is apparently increased by the mineral elements, 

 while nitrates lessen the variability. With beans potash produced the greatest increase 

 in the number of pods, nitrates next. Gates (London). 



204) Blaringhem, L., Phenomenes de xenie chez le ble. In: C ß. Academie des 

 Sc, Bd. 156, Heft 10, S. 802—804, 1913. 



En effectuant du croisements chez diverses especes de ble, l'auteur a obtenu pour 

 la premiere fois, chez le ble, des phenomenes de Xenie. C. L. Gatin (Paris). 



205) Buchet, S. (Sorbonne, Laboratoire de Botanique), La pretendue heredite des 

 maladies cryptogamiques. In: Bull. Soc. Bot. de France, Bd. 59, Heft 8, S. 754 

 bis 762, 1912. 



Polemikartikel. C. L. Gatin CParis). 



206) Dobell, C. (London, Imperial College of Science), Some Recent Work on 

 Mutation in Microorganisms. Part IL Mutations in Bacteria. In: 

 Journ. of Genetics, Bd. 4, S. 325—350, 1913. 



The author reviews recent work on inherited changes in Bacteria, classi- 

 fying them into (a) physiological, and (b) morphological. A considerable part of 

 the paper deals with apparently adaptive mutations, the power of Bacilli of the 

 coli-typhosus group to give rise to daughter-colonies which can ferment sugars 

 when grown in sugar-containing media. He also gives cases of mutations (usu- 

 ally in colour) induced by chemical means, and notes that the same reagent may 

 give rise to different mutations in the same strain. Many of the mutations des- 

 cribed appeared spontaneously, without any recognisable external cause. The 

 mutations differ from 'modifications' which are induced by change of medium, 

 in being permanent when the organism is restored to its former medium, whereas 

 'modifications' disappear under such circumstances. Doncaster (Cambridge j. 



207) >Vel)ber, H. J., The Effect of Research in Genetics on the Art of 

 Breeding. In: Amer. Breeders' Mag., Vol. III, Nr. 1, S. 29—36, Nr. 2, S. 125 

 bis 135, 1912. 



An address given by the retiring chairman of the Plant Section, of Amer. 

 Breeders' Assoc, Dec. 30, 1911. Nvmierous results of both plant and animal 

 breeders are given to show that the greatest weight of evidence is opposed to 

 the origiu of a new unit character through the cumulative action of selection. 

 The author discusses the value of continuous selection to the practical breeder, 

 while at the same time pointing out the fact that each individual case will re- 

 quire careful analysis in order to determine the nature of the advance made and 

 the interpretation of the process or processes concerned. The origin of new unit 

 characters, if not produced by selection, is discussed. The author is inclined to 

 believe that it will be found that hybridization may stimulate the production of 

 new unit characters which mendelize with the parental types. Pearl (Orono). 



