Neue Litteratur. 5 



Haas, A. R. 1916. The excretion of acids by roots. (Proc nation. Ac. 



Sc. U. 3 A. II. p. 561—566.) 

 Habler, L. 1916. Das Kälteverfahren in der Gärtnerei. (Prometheus. 



XXVII. p. 824-827. 1 A.) 

 Harris, J. A. and W. Popenoe 1916. Freezing-point lowering of the 



leaf sap of the horticultural types of Persea americana. (Journ. 



agr. Res. VII. p. 261—268.) 

 Hartwell, B. L. 1916. Starch congestion accompanying certain fac- 



tors which retard plant growth. (Bull. Rhode Island agr. Exp. 



Stat. 1916. 165. p. 3-23.) 

 Heropel, J. 1916. Bidrag tili kundskaben om Sueculenternes Fysio- 



logi. Plantefysiologisk Studie. (Kjöbenhavn 1916. 8°. 156 pp.) 

 Holman, R. M. 1916. Tbe orientation of primary terrestrial roots 



with particular reference to the medium in whieh they are grown. 



(Amer. Journ. Bot. III. p. 274—318. 7 f.) 

 Jacoby, M. 1916. Studien zur allgemeinen Vergiftungslehre. III. Ueber 



die Reizwirkung des Lecithins auf die Fermentbildung. (Biochem. 



Zschr. LXXVII. p. 124—128.) 

 Jörgensen, I. and F. Kldd. 1916. Some photochemical experiments 



with pure Chlorophyll and their bearing on theories of carbon 



assimilation. (Proc. r. Soc. London. B. LXXXIX. p. 342—361.) 

 Knudson, L. 1916. Influence of certain carbohydrates on green plants. 



(Mem. Cornell Univ. Agr. Exp. Stat. 1916. 9.) 

 Lawrence, H. 1913. The influence of the radiations of radium upon 



the germination of seeds (Oats). (Austral. Ass. Adv. Sc. XIV. p. 



325—326.) 

 Lloyd, F. E. 1916. The abscission of fiower-buds and fruits in Gos- 



sypium, and its relation to environmental changes. [Abstract]. 



(Trans, r. Soc. Canada. 3. X. p. 55—61.) 

 Loeb, J. 1916. On the association and possible identity of root-for- 



ming and geotropic substances or hormones in Bryoph}^llum ca- 



lycinum. (Science. 2. XLIV. p. 210—211.) 

 Lundegärdh, H. 1916. Die Orientierungsbewegungen der Blätter von 



Buche und Ahorn. (Svensk bot. Tidskr. X. p. 438-470. 14 A.) 

 Mc Dougal, W. B. 1916. The growth of forest tree roots. (Amer. 



Journ. Bot. III. p. 384-392.) 



Tu. Palaeontologie. 



Arber, E. A. N. 1916. On the fossil floras of the coal measures of 



South Staffordshire. (Philos. Trans, r. Soc. London. B. CCVIII. p. 



127-155. pl. 2—4.) 

 Bassler, H. 1916. A cycadophyte from the North American coal 



measures. (Amer. Journ. Sc. 4. XLII. p. 21 — 26.) 

 Berry, E. W. 1916. The physical conditions and age indicated by the 



flora of the Alum Bluff formation. (U. S, geol. Surv. prof. Pap. 



98 E. 1916. p. 41—59. 4 pl. 1 f.) 

 Berry, E. W. 1916. The physical conditions indicated by the flora 



of the Calvert formation. (U. S. geol. Surv. prof. Pap. 98 F. 1916. 



p. 61—73. 2 pl.) 

 Grüss, J. 1916. Die Kalkwurzeln von Waltersdorf. (Ber. deutsch, bot. 



XXXIV. p. 456-469. 1 A. 1 T.) 

 Nagel. 1916. Betulaceae. Fossilium catalogus. II. Plantae. Pars 8. 



177 pp. (Berlin, W. Junk. 1916. 8°.) 



VIII. Microscopie. 



Kaiserling, C. 1916. Lehrbuch der Mikrophotographie. 2. Aufl. bearb. 



