March 1908.] 



RECENT ARTICLES IN THE 

 LITERATURE. 



229 



Miscellaneous 



Fibre J' Ananas. Journ. d'Agr. trop, 

 Nov. 30. 1907, p. 823. 



Camphre naturel. do. 335. 



A Seringueira (Hevea brasiliensis). 

 Ruber. Para 1907. 



Gerber-riiide. Der Pflanzer 1907, p. 252. 



Zimrnermann. Ueber einige Griindung- 

 ungsversuche mit LeguniinossB. Der 

 Pflauzer 1907, p. 152. 



Zimrnermann. Anzapfungsversuche 

 mit Kickxia elastica. do. p. 182. 



The history of the cowpea and its 

 introduction into America, U. S. Dept. 

 Agr., R. P. I Bull. 102. 1907. 



Stange, Der Kork, Seine Verwenduug 

 und Produktion. — Tropenpflanzer, May 

 1907, p. 314. 



' Webber and Boykin. The advantage 

 of planting heavy cotton seed.— U.S. 

 Department of Agriculture. Farmer's 

 Bull. 285, 1907. 



Howard. First report on the fruit 

 experiments at Pusa.— Bull, 4. Agricul- 

 tural Research Institute, Pusa. 



Alexander und Bing. Ueber die 

 Gewinnung von Kautschuk aus getro- 

 chueten Kautschukpenpflanzen. — Tro- 

 penpflanzer, Feb., 1908, p. 57. 



Von Faber. Ueber Verlaubung von 

 Cacaobliiten Berichte dentsch. Bot. Ges. 

 25. 1908, p. 577. 



Henry. Le Caoutchouc en Afrique 

 occidentale francaise. — Bull. Jard. Col. 

 Dec. 1907, p. 457. 



Phoenix dactylifera, the date palm. 

 — Agric. Ledger, Calcutta, Veg. Prod. 

 Series No. 93. 



TRANSPIRATION AND AN 1TOMICAL 

 STRUCTURE IN TROPICAL PLANTS. 



Der Einflrtss des Klimas auf den Bau 

 der Pflanzeng webe. AnatomUch-physio- 

 loginche Untersuchungen in den Tropen. 

 By Dr. Carl Holtermann. Pp. viii + 219; 

 plates. (Lei pzig ; W. Engelmann, 1907.) 

 Price 12 marks. 



Dr. Holtermann's investigations, main- 

 ly carried out in Ceylon, include a long 

 series of experiment'-' on the transpiration 

 of different tropical plants. His tables 

 show great variations in the amount of 

 transpiration for the same plant during 

 the same hours of different days, and 

 these are in many cases not explained by 

 the differing temperature and relative 

 humidity, which are the only other data 

 given. Thus, for instance, in the case of 

 Cannct indica, between 9-40 a.m. and 

 30 



5-40 p.m. on January 11 (with a relative 

 humidity ot 61 and a temperature of 

 25° - 4 at 10 a.m.), the transpiration was 

 37 gr. per hour per sc^. dm. of leaf 

 surface, while on January 17, between 

 9-45 a.m. and 5-30 p.m. (R.H. 63, temp. 

 26°-2. at 11-15 a.m.), the transpiration 

 was 92 gr. per hour per sq. dm., and 

 on January IS between 9-15 a.m. and 3-30 

 p.m. the transpiration was2'60gr. per hour 

 per sq. dm. (no humidity or temperature 

 data are given within the period of the 

 experiment, but judging from the late 

 afternoon figures the day did not differ 

 much from the others). This, though 

 an extreme case, is only one out of 

 several similar ones, and the effect of 

 such figures on the reader is decidedly 

 bewildering, though the striking vari- 

 ations may be explicable by changes of 

 insolation, or the irregular occiu'rence or 

 drying winds. As they stand, the author's 

 figures only demonstrate that the trans- 

 piration of the plants studied exhibited 

 startlingly wide fluctuations which re- 

 niian quite unexplained. 



The author's general conclusion from 

 his experiments is that while the highest 

 transpiration figures per hour in the 

 tropics are considerably higher than any 

 north European ones, yet active trans- 

 piration begins later and stops earlier in 

 the day in the case of a damp tropical 

 climate, so that the daily average is no 

 higher than in Europe, while in the wet 

 season transpiration may cease for 

 weeks at a time. He thus does not 

 disagree with the conclusions either of 

 Haberlandt or of Giltay on this question. 

 Dr. Holtermann holds that water-tissue 

 is essentially an arrangement to supply 

 water to the transpiring tissues during 

 these short periods of excessive evapor- 

 ation, not a means of lessening transpira- 

 tion, and this view he supports by 

 showing that it is especially developed 

 in actively transpiring plants liable to be 

 subjected to these sudden demands. It 

 is characteristic of the leaves of tropical . 

 plants growing in a climate which is 

 neither quite xerophytie nor constantly 

 moist, and this harmonises with the short 

 daily period of very active transpiration 

 already mentioned, The mangroves, 

 which ordinarily possess characteristic 

 water-tissue, well developed, from much 

 less or none at all in the leaves of ex- 

 amples cultivated in garden soil, which 

 transpire very much more freely than 

 plants growing in the natural salty soil, 

 if these plants cultivated without salt 

 are now watered with 3 percent, salt 

 solution and placed in the sun, ttiey show 

 a wilting of the leaves, and the meso- 

 phyll becomes shrivelled. Mangroves 

 growing in their natural habitat also 

 show wilting on hot afternoons, but only 



