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



580. Gleasox, H. A. Variability in flower-number in Vernonia missurica Raf. Amer. 

 Nat. 53: 526-534. Nov.-Dec, 1919. — Statistical study of a few plants indicates number of 

 flowers to be greatest in terminal heads of each cyne. Range of variability of flower number 

 is smaller for individual plants than for entire population. — Helene Boas Yampolsky. 



581. Gleason, H. A. The history of the London plane. Jour. New York Bot. Gard. 20: 

 216-220. Nov., 1919. — Largely extracts from "The history of the London plane" by A. Henry 

 and M. G. Flood in Proceed. Royal Irish Acad. Describes in some detail histor}^ of the Lon- 

 don plane, Platanus acerifolia, usually regarded in the United States as Platanus orientalis. 

 Former is common street tree, has remarkable vigor, and is very resistant to smoke, drought 

 and other unfavorable city conditions. P. orientalis is rarely planted as street tree. London 

 plane probably a first-generation hybrid between P. orientalis and P. occidentalis, which ex- 

 plains its remarkable vigor and the great variability of its seedlings, part of which are similar 

 to supposed parents, and part combine characters of both parents in various ways. Possibly 

 originated at Oxford Botanic Garden about 1670 from chance hybridization. Experimental 

 proof for this assumption could be obtained in the United States where adult trees of both 

 natural species are to be found. — O. E. White. 



582. Godfrey, M. J. The problem of the British orchids. Jour. Botany 57: 137-142. 

 1919— See Bot. Absts. 3, Entry 148. 



583. Goetz, E. Tabakanbauversuche. [Tobacco culture investigations.] Badisches 

 Wochenbl. 1919:67-69. 1919. 



584. Gouveia, J. T. Climatic conditions as indicated by land shells on the island of Oahu. 

 Nautilus 33: 89-92. Jan., 1920. — Discusses differences in distribution of dextral and sinistral 

 shells of Achatinella cesius. — J. Arthur Harris. 



585. Gowen, J. W. Variations and mode of secretion of milk solids. Jour. Agric. Res. 

 16: 79-102. 1919. — A study based on the advanced registry records of the Holstein-Friesian 

 Association. The mean, standard deviation, and coefficient of variation are given for quantity 

 of milk produced in a year, age, quantity and percentage of butter fat and solids-not-fat. The 

 average constitution of Holstein-Friesian milk as thus found is compared with the available 

 data from other breeds of cattle and from other kinds of mammals. A slight, but significant, 

 negative correlation (— 0.098 ± 0.016) is found between quantity of milk and percentage of 

 butter fat.* The correlation between quantity of milk and percentage of other solids is also 

 negative (— 0.066 ± 0.037) but not significant, being smaller as well as based on fewer cases. 

 Age is not found to be correlated to a significant extent with percentage of butter fat (—0.055 

 = fc 0.018) but is correlated (negatively) with the percentage of other solids (— 0.019 ± 0.035). 

 The quantity of butter fat and of solids-not-fat are found to vary together, the partial 

 correlation between them for a constant amount of milk, being +0.564 ± 0.025. Data are 

 presented on the difference in the constitution of milk in the morning and evening. Evening 

 milk is found to be distinctly the richer in fat content but not appreciably different in solids- 

 not-fat. The bearing of the data on the different theories of milk production is discussed. It 

 is held that they favor the theory that milk is produced by secretion and not by cell disin- 

 tegration. — Sewall Wright. 



586. Gowex, J. W. Report of progress on animal husbandry investigations in 1917. Maine 

 Agric. Exp. Sta. Bull. 274: 205-228. ,? pi, 1 fig. 1918.— (1) Analysis of milk records: Rela- 

 tion of age to milk and fat production in Guernseys was studied, using correction factors 

 found; influence of sires was studied on the basis of production of daughters compared to pro- 

 duction of dams of these daughters. — (2) Variations and mode of secretion of milk solids: Short 

 account of investigations, results of which have been published in Journal of Agricultural 

 Research. 16: 79-105. 1919. — (3) Cattle judging as a means of selecting cows for the herd: 

 Study was made of correlation between milk production and scores of 672 cows. Conclusion 

 is reached that high-producing cows ran be select ed by external conformation only when two 



