378 W. Wen dl er: Chemische Physiologie 1921— 1922 [18 



einigen Hefen. (Journ. of the College of Science, Imperial University of 

 Tokyo 34, 1916.) — Ref. in Zeitscbr. f. Bot. 15, 1923, 1, p. 56—57. 



181. Scheer, K. Über die Beziehungen der Darmbakterien zur 

 Wasserstoffionenkonzentration. (Zeitschr. f. Immunitätsforsch, u. exp. 

 Therapie, I. Orig. XXXIII, 1921, p. 36—42.) — Ref. in Bot. Ctrbl., N. F. I, 

 1922, p. 173. 



182. Schneidevvind, W. Die Kalidüngung. (4., neubearb. Aufl. 

 Berlin, Paul Parey, 1922. 72 pp., mit 4 färb. Taf.) — Enthält: A. Der Kali- 

 gehalt des Bodens. B. Die Löslichkeit des Kalis der verschiedenen Bodenarten. 

 C. Die Ausnutzung des Bodenkalis durch die verschiedenen Kulturpflanzen 

 und ihr Bedarf an Kali im allgemeinen. D. Unter welchen Verhältnissen 

 wird Raubbau an Kali getrieben? E. Die kalkhaltigen Düngemittel: 1. Der 

 Stalldünger. 2. Die Kalisalze. 3. Phonolithmehl. F. Die Düngung der ein- 

 zelnen Kulturpflanzen: 1. Weizen. 2. Roggen. 3. Gerste. 4. Hafer. 5. Kar- 

 toffel. 6. Zuckerrübe. 7. Futterrübe. 8. Raps, Mohn. 9. Leguminosen. 

 10. Wiesen und Weiden. G. Beispiele für die Anwendung der Kalisalze in 

 den verschiedenen Fruchtfolgen. Bessere Böden. Leichtere Böden. Moor- 

 böden. 



183. Schweizer, K. Der Aminostickstoff und die Lufthefe. 

 (Bull. Assoc. Chim. de Sucr. et Dist. XXXVI, 1918, p. 52—56.) 



184. Sears, P.E. Variations in cytology and gross morpho- 

 logy of Taraxacum. II. Senescence, rejuvenescence and leaf Varia- 

 tion in Taraxacum. (Bot. Gazette LXXIII, 1922, p. 425—446, mit 9 Text- 

 figuren.) — Ref. in Bot. Ctrbl., N. F. 2, 1923, p. 83—84. 



185. Sherman, J. M. and Holm, G. E. Salt Effects in Bacterial 

 Growth. II. The Growth of Bacterium Coli in Relation to H-Ion 

 Concentration. (Journ. of Bacteriology 7, 1922, p. 465 — 470.) — Ref. in 

 Bot. Ctrbl., N. F. II, 1923, p. 241. 



186. Sjörstedt, H. Gm j ärnutf ällning hos hafralger ved Skänes 

 kuster. (Bot. Notiser, 1921, p. 101—130.) — Ref. in Bot. Ctrbl., N. F. I, 

 1922, p. 47. 



187. Smith, T. 0. and Butler, 0. Relation of Potassium to Growth 

 in Plauts. (Ann. of Bot. 35, 1921, p. 189—225, mit 31 Tabellen.) — Summary: 

 ,,1. The reserve supply of potassium in the seed is not sufficient to maintain 

 normal growth except for a very short period of time. 2. Symptoms of po- 

 tassium starvation appear early in the life of a plant and are characterized 

 by a dwarfing of the axis and progressive death. of the foliage, the older leaves 

 suceumbing first. 3. The potassium absorbed per gramme of dry matter 

 formed is higher in plants growing in the presence of potassium than in plants 

 growing in its absence. 4. Recovery from potassium starvation occurs the 

 more slowly the longer potassium is whitheld. 5. Tlie relative distribution 

 of potassium per gramme of dry matter formed as between tops and roots 

 is the same whether the plants are growing in the presence of potassium, in 

 the absence of potassium, or have first suffered from a more or less prolonged 

 period of starvation. 6. When potassium-starved plants are supplied with 

 potassium the element becomes distributed promptly in accordance with the 

 physiological needs of the plant, the absorption progressing with marked 

 rapidity. 7. The normal life cycle is inhibited in potassium-starved plants 

 and more or less delayed by partial potassium starvation. 8. The relative 

 potassium requirement per gramme of dry matter formed as between the 



