NOTES AND ABSTRACTS. 



177 



Species. Both are hardy, and love, a deep, moist, well-drained soil 

 and a shady place. Propagation is by division or seeds, sown as soon 

 as ripe.^ — H. R. D. 



Primulas, Mew {Gartenflora, vol. Ixii. pt. xxiii. pp. 506-508). — 

 There is no difficulty in growing the new Primulas Bulleyana, Cock- 

 burniana, pulverulenta, Veitchii, ' La Lorraine,' and Juliae. They 

 should be planted in well-drained beds of light soil, rich in humus. 

 Shade from the sun at noon and give some protection in winter. 

 ' La Lorraine ' is an improvement on Veitchii, as it is more vigorous 

 in growth and more floriferous. The flowers are carmine-pink with 

 a yellow eye. — 5. E. W, 



Pure Strains of Plants, Can Selection Improve the Quality of? 



By C. Hagedoorn and A. Hagedoorn [Jour. Bd. Agr. vol. xx. No. 

 10, pp. 857-860 ; plate). — ^The authors briefly discuss the behef, 

 to which many people adhere, that as soon as selection ceases the 

 variety will begin to deteriorate. The experiments of Johannsen, 

 who concluded that selection had no effect whatever on a pure strain, 

 are cited. These experiments, however, have been regarded as in- 

 conclusive because of the small number of generations during which 

 they have been mxade. A comparison of specimens of wheat selected 

 by Louis de Vilmorin about 1850 with plants of the same strains 

 grov/n in 1911 leads the authors to the conclusion that in no respect 

 have the sixty years of selection produced a change. They are of the 

 opinion that once a strain is pure for all its genetic factors it is possible 

 to grow its seed year after year without fear of its deteriorating. 

 " Wheat, or barley, or oats can be of so pure a strain that no amount 

 of selection can possibly ameliorate them, and no amount of selection 

 in the opposite direction can deteriorate them." 



" On the other hand, in the case of habitually cross-fertilized plants, 

 such as rye and beet, continued selection by experts is most necessary 

 in order to keep the quality of the seed up to the standard, as under 

 practical conditions no really pure strain can ever be produced by 

 such plants. In these plants the seed deteriorates by multiplication 

 without selection, and it is very probable that, by an unwarranted 

 generalization, it has come to be believed that the same holds true 

 for all agricultural plants." — A. S. 



Pyrethrum of Dalmatia, The, Its Growth in Provence {Jour. 

 Soc. Nat. Hort. Fr. May 1913, p. 270). — Some experiments in culti- 

 vating Pyrethrum cinerariaefolium in Southern France with a 

 view to the production of Pyrethrum powder were made some years 

 ago and proved quite successful from the cultural point of view. 

 The plants did well, flowered freely, and proved both to be more 

 flourishing and to produce flowers containing a larger percentage of 

 the active principle of the Dalmatian insecticide if they were left 

 to themselves with the minimum of cultural care. The industry 

 was afterwards abandoned in France, however, as it was found that 



VOL. XL. N 



