Physiologie. 135 



'to 



Delf, E. M., Transpiration in Succulent Plants. (Ann. of Bot. 

 XXVI. p. 409-440. 1 text fig. 1912.) 

 A summary of existing knowledge, supplemented by a number 

 of new observations, many of which refer to halophytes. The 

 memoir is considered in two sections; transpiration in relation lo 

 structure, and in relation to habitat. The transpiring surface may 

 occur on more or less reduced leaf-surfaces, or on fleshy leaves 

 without reduction. Taking as a criterion of succulence the percen- 

 tage water-content of a plant, there is a table giving the water- 

 content per sq. dem; succulents {Suaeda, etc.) have 5—12 grams, 

 semi succulents {Aster tripolium, etc.) 2—5 grs , and mesophytes 

 {Merciirialis anniia, etc.) 1 — 2 grs. water. As regards rate of trans- 

 piration, if water = 100, then Salsola, Mesernbrynntheminn, etc. 

 give 60—67, Salicornia 32, and Vicia, etc. 26—28. It is shown that 

 a large number of succulents show little cuticlc but can endure a 

 rapid rate of transpiration. An examination of the distribution of 

 stomata leads to conclusion that although these are often protected, 

 yet in many succulents the stomata are apparently unprotected. 

 Absorption of water by the epidermis or its appendages is aLso 

 common. The distribution of the water-storage System is reviewed, 

 and it is suggested that the formation of these tissues is related to 

 the production of organic acids within the plant, along with presence 

 of Chlorides or sulphates in the soil. The behaviour and water- 

 content of representative succulents in course of withering is dealt 

 with. A summary of past work on transpiration in relation to 

 habitat leads to the conclusion that many adaptations are of real 

 value to the plant, whether produced during the lifetime of the 

 individua) or present as permanent features of the species. 



W. G. Smith. 



Teodoreseo, E. C, Assimilation de l'azote et du Phos 

 phore nucleique par les Alguesinferieures. (C. R. A. Sc 

 Paris CLIII. p. 300—303. 1912.) • 



L'auteur conclut de ces recherches que certaines Algues infe- 

 rieurs peuvent desintegrer la molecule de Tacide nucleique et mi- 

 neraliser le phosphore organ^que de cet acide. Le dedoublement 

 parait du ä la nuclease, ferment specifique des nucleines. L'azote 

 et le phosphore nucleiques peuvent servir d'aliments ä ces algues 

 et paraisent etre dans les premiers temps tres favorables ä un deve- 

 loppement rapide et abondant, plus meme que l'azote et le phos- 

 phore offerts sous la forme minerale. 



L'Algue mise en experience elait le Chlamydomonas reticiilata. 



P. Hariot. 



Ulrich, E. B., Leaf movements in the family Oxalidaceae. 

 (Contr. Bot. Lab. Univ. of Penna 3. p. 211—242. pl. 3. f. 1—5. 1911.) 



The experiments conducted by means of a clock-driven Kymo- 

 graph. record by means of graphic figures the normal movements 

 and the movements under Stimuli of the leaves of Oxalis bupleuri- 

 foUa, Averrhoa carambola, Oxalis lasiandra, O. stricta, O. arborea 

 coccinea, O. deppei, O. catharinensis, 0. niartiana, O. scandetis, 

 O. vespertüionis. A bibJiography is given. Harshberger. 



