222 GENETICS [Bot. Absts., Vol. V, 



society of growers interested in applying theoretical knowledge to their own problems. Rec- 

 ords of practical breeders' work should be kept by a central body. Work is often repeated 

 through lack of an organization through which knowledge can be distributed. Many a valu- 

 able discovery has probably been made by individual workers and then lost to the world 

 because the records have not been passed on. Author says "Darwin's theories today are 

 repudiated to a large extent, while Mendel's law is recognized." — Orland E. White. 



1675. Thomson*, J. Arthur. [French rev. of: Macleod, J. The quantitative method in 

 biology. 15x23 cm.,v+228 p., 27 fig. Longmans, Green & Co.: New York, 1919. (See also 

 Bot. Absts. 4. Entry 758.)] Scientia 27: 244-246. 1920. 



1676. Tischler, G. [German rev. of : (l) Renner, O. Ueber Sichtbarwerden der Mendel- 

 schen Spaltung im Pollen von Oenotherabastarden. (On the visibility of Mendelian segrega- 

 tion in hybrids of Oenothera.) Ber. Deutsch. Bot. Ges. 37: 129-135. 1919. (2) Idem. ZurBiol- 

 ogie und Morphologie der mannlichen Haplonten einiger Onotheren. (Biology and morphology 

 of the male haplonts of some Oenotheras.) Zeitschr. Bot. 11: 305-380. 39 fig. 1919.] Zeit- 

 schr. indukt. Abstamm. Vererb. 22: 221-223. Mar., 1920. 



1677. Tornau, Dr. Einige Mitteilungen uber variabilitatsverhaltnisse in einem kon- 

 stanten Weizenstamm. [Some communications concerning variability relations in a constant 

 wheat strain.] Jour. Landw. 67: 111-149. 1919. — A biometrical study of variability and cor- 

 relation in a pure line of wheat, the constants for different years being compared. — C. E. 

 Lcighty. 



1678. Van Fleet, W. Rose-breeding notes for 1918. Amer. Rose Ann. 1919 : 29-35. 1919. 

 — Description of results from crossing numerous species and types of roses. Considerable 

 improvement is seen in newer hybrids of Rosa rugosa, R. Hugonis, R. Soulieanea, R. Moyesii. 

 Color range in R. rugosa hybrids covers single and double, constant-blooming forms in clear 

 whites to glowing crimsons. No pure yellows. Creams, common and bright yellows may be 

 expected in time. Main ideal for R. rugosa hybrids is high class blooms of Hybrid Perpetual 

 and Hybrid Tea types combined with vigorous, hardy, disease-resistant plants. Premier 

 English rose of 1918 is Mermaid, said to be result of R. bracleata crossed with a tea-scented 

 variety. Efforts are being made to secure hybrids of R. bracteata able to endure climate of 

 northern plains region, hybrids of R. bracteata X R. Carolina giving promising results, and 

 enduring zero weather. They have beautifully-formed pink buds. No success has been 

 attained in attempts to cross Harison's Yellow for over 20 years. More success with seedlings 

 of this variety, especially one similar to one of reputed parents of Harison's Yellow. Out of 

 many thousand seeds of Harison's Yellow sown, only three grew so far. There is possibility 

 of fragrance of the sweetbrier being intensified through breeding work. — Orland E. White. 



1679. van Wisselingh, C. Uber Variabilitat und Erblichkeit. [Concerning variability 

 and heredity.] Zeitschr. indukt. Abstamm. Vererb. 22 : 65-126. 10 fig. Jan., 1920. — Empha- 

 sizes importance of a study of the lower and simpler plants in the attempt to get at 

 fundamentals of heredity and variation. Many illustrations are cited from author's and 

 Gerassimoff's extensive studies of S-pirogyra. Variations in the form and size of the cell, 

 thickness and markings of cell walls, number and form of chromatophores, presence or absence 

 of pyrenoids and method of starch-formation, number of nuclei, abnormalities in nuclear and 

 cell-division, number of chromosomes, and nature and development of nucleoli are described 

 in detail, and the causes giving rise to them are discussed. Variations in cell length, rate of 

 starch formation and cell division may be induced through alterations in amount of light, but 

 are not heritable. Thickness and markings on cell walls are heritable even in cells without 

 nuclei. Chromatophores without pyrenoids form starch in a diffuse manner and are passed 

 on through innumerable cell generations regardless of environmental conditions. Binucleate 

 cells may be produced through anaesthesia, low temperatures, or centrifuging. This condi- 

 tion is perpetuated by cell division and so is heritable. Instead of two nuclei there may be 

 one giant nucleus. In either case the cells assume a much larger diameter which is inherited 



