74 GENETICS [Bot. Absts., Vol. IV, 



pointed out. As a rule seed should not be taken from a region of relatively mild climate to 

 one of more severe climate. Experimental plantations show a variation in number of good 

 plants of from 1 per cent to 76 per cent for seed from different localities. A difference of 

 1°C. in mean annual temperature, or 200 meters in altitude is sufficient to show a marked 

 effect upon the development of plants from a given lot of seed. The pine {Pinus sylvestris) 

 requires a mean temperature of 10° to 11°C. from June to August inclusive to produce germin- 

 able seed. In the extreme northern range and in high altitudes this temperature is seldom 

 attained, with the result that the forests are irregular and many-aged. The country is 

 divided into regions according to the average germination of pine seed, which corresponds 

 closely to the mean June-August temperature. Seed of the highest viability is produced 

 when the mean June-August temperature is 13 °C. Pine seed often shows a higher germina- 

 tion per cent after it has been stored 1 or 2 years. The spruce (Picea excelsa) produces 

 germinable seed in a mean June-August temperature, about 1°C. lower than that required 

 by pine. Since the spruce is relatively independent of temperature, no definite relation 

 between viability of seed and climatic factors have been found. — G. A. Pearson. 



484. Wimmexatjer, K. Wachstum und Ertrag der Esche. [Growth and yield of ash.] 

 Allg. Forst- u. Jagdzeitg. 95 : 9-17. 1919. — Article is one of series, to be concluded in February 

 number of this journal. Detailed results (tables) based on sample plot investigations. — 

 Hermann Krauch. 



GENETICS 



Geokge H. Shull, Editor 

 James P. Kelly, Assistant Editor 



485. Adametz, L. Uber Wesen und Ursprung der Domestikationsmerkmale bei Mensch 

 und Tier. [The existence and origin of marks of domestication in man and animals.] Sitz- 

 ungsber. anthropol. Ges. Wien 48:4-9. 1918. — Author discusses the various physical and 

 mental characteristics, largely of a degenerative nature, which tend to appear among ani- 

 mals under domestication and in the human race which he holds is living under similarly 

 unnatural conditions. — Sewall Wright. 



486. Allen, C. E. The basis of sex inheritance in Sphaerocarpos. Proc. Amer. Philos. 

 Soc. 58: 289-316. 28 fig. 1919. — Few small counts from separately sown tetrads suggest that 

 2 spores of tetrad develop male, other two female gametophytes. Female shows 8 chromo- 

 somes, 1 (X) distinctly larger; male 8, 1 (Y) inconspicuous; sporophyte about*16, just 1 (X) 

 distinctly larger. Heterotypic division not seen; homotypic shows X present in 1 spindle, 

 absent in other. Novel mechanism, for diploid generation (asexual) is regularly heterozy- 

 gous. X, due to greater bulk, brings "vigor" in female gametophyte, male being much 

 smaller (consisting of fewer, not smaller, cells). "Quantitative theory" of sex determination 

 is "impossible of application" in Sphaerocarpos, for sex individuals show no trace of oppo- 

 site sex characters. — Merle C. Coulter. 



487. Alverdes, F. [German rev. of: Bonne vie, Kristine. Polydaktyli i norske bygde- 

 slegter. (Polydactyly in Norwegian peasantry.) Norsk Mag. f. Lagev. 6: 1-32. 1919. (See 

 Bot. Absts. 4, Entry 3314.)] Zeitschr. indukt. Abstamm. Vererb. 22: 142-143. Jan., 1920. 



488. Alverdes, F. [German rev. of: Bonnevie, Kristine. Om tvillingsfodslers arve- 

 lighet. Undersokelse over en norsk bygdeslegt. (On the inheritance of twin births. Inves- 

 tigations on Norwegian peasantry.) Norsk Mag. f. Lagev. 8: 1-22. 1919. (See Bot. Absts. 

 4, Entry 3315.)] Zeitschr. indukt. Abstamm. Vererb. 22: 143-144. Jan., 1920. 



489. Anonymous. Old age in perennial plants. Gard. Chron. 66: 190. Oct. 11,1919. — 

 Refers to the discovery of H. M. Benedict (Cornell Agric. Exp.Sta. Mem. 7, 1915) that the 

 wild grape (Vitis vulpina) and certain other woody perennials with increasing age have 

 correspondingly closer-meshed veins in their leaves, a condition which is regularly propagated 

 by cuttings. — John Belling. 



