54 TAXONOMY OF VASCULAR PLANTS [BoT. Absts., Vol. X, 



investigation. The soils on which the pecan experiments are located are the Greenville 

 sandy loam, Orangeburg sandy loam, and the Norfolk sandy loam. For best growth and 

 development of a young orchard, a complete fertilizer high in nitrogen has given best results. 

 Older orchards have a somewhat higher phosphate requirement. The amount of nitrogen in 

 the fertilizer used can be reduced where leguminous cover crops are grown and plowed under. 

 The fertilizer combinations giving maximum yield increased nut production from 20 to 35 

 per cent. — /. J . Skinner. 



320. Truffaut, G., et N. Bezssonoff. Augmentation du nombre des Clostridium 

 Pastorianum (Winogradski) dans des terras partiellement sterilisees par le sulfure de calcium. 

 [Increase in the number of Clostridium Pastorianum organisms in soil partially sterilized by 

 the addition of calcium sulphide.] Compt. Rend. Acad. Sci. Paris 172: 1319-1322. 1921. — 

 It is contended that Clostridium Pastorianum and not Azotobactcr is the principal agent of 

 nitrogen fixation in the soil. Clostridium Pastorianum was found to the extent of 100,000 

 colonies per gr. against 500 of Azotobacter. The highest number reported for Azotobacter 

 is 1800 per gr.— C. //. Farr. 



321. Williams, C. O. The soils of Natal and the Transvaal. I. The composition of Natal- 

 soils. South African Jour. Indust. 4: 177-181. 1921. — The soils generally are acid and are 

 characterized by the complete absence of calcium carbonate, except the soils of the Ladysmith 

 and Weenen districts, which are alkali soils. The phosphate content is low and the potash 

 content normal. — J. J. Skinner. 



TAXONOMY OF VASCULAR PLANTS 



J. M. Greenman, Editor 

 E. B. Payson, Assistant Editor 



(See also in this issue Entries 25, 128, 262) 



GENERAL 



322. Anonymous. [Rev. of: Britton, N. L., and C. F. Millspaxtgh. The Bahama 

 flora, via + 695 p. The authors: New York Botanical Garden; Dulau and Co.: London, 

 1920 (see Bot. Absts. 7, Entry 1429).] Nature 107: 327-328. 1921. 



323. Anonymous. [Rev. of: Horwood, A. R. A new British flora: British wild flowers 

 in their natural haunts. (In 6 vols.) Vol. 1, ix + 2U P-', vol. 2, xi + 243 -p., 17 pi. The 

 Gresham Publishing Co.: London, 1919.] Nature 107: 232. 1921. 



324. Anonymous. [Rev. of: Shoolbred, W. A. The flora of Chepstow, x + UO p, 

 Taylor and Francis: London, 1920.] Nature 106: 564. 1920. 



325. Hitchcock, A. S. The type concept in systematic botany. Amer. Jour. Bot. 8: 

 251-255. 1921. — The author points out the importance of codes of nomenclature in stabilizing 

 the naming of plants and indicates the advantages resulting from the Paris Code of 1867 and 

 the Vienna Code of 1905. These have been found, however, to lack definiteness in directing 

 the application of names. Names were originally applied rather to concepts than to entities. 

 During the last 30 years the system of applying names by means of types has grown up in 

 America and the type concept lies at the basis of modern botanical nomenclature. It is not 

 referred to in the Paris and Vienna Codes, but was recognized by the American Code and by 

 the Brussels Congress. The Type-basis Code, formulated by the Committee on Nomencla- 

 ture of the Botanical Society of America, is described and its operation illustrated by various 

 examples. The advantages of accepting the concept of types are pointed out, and it is shown 

 that this does not involve the acceptance of any particular set of rules for selecting types. — 

 E. W. Sinnott. 



