1919] 



AGRICtTLTURAX. BOTANY. 329 



The influence of immersion in certain electrolytic solutions upon perme- 

 ability of plant cells, M. Williams (Ann. Bot. [London], 32 {1918), No. 128, pp. 

 591-599, figs. 2).— In an attempt to discover what factors besides surface ten- 

 sion may be involved in alterations of permeability in plant cells and bow far 

 the time of immersion in a particular solution may be significant, the author 

 has experimented with surface strips taken from leafstalks of Saxifraga um- 

 Irosa in solutions of electrolytes. He has found that immersion in these solu- 

 tions rendered these cells permeable to 0.2 per cent ferric chlorid as indicated 

 by reaction of the ferric chlorid with the tannin contained in the cells, the time 

 required for the production of the abnormal permeability depending upon the 

 concentration. Abnormal permeability to iron chlorid did not involve permeabil- 

 ity to the rose-colored material which was observed frequently in the cell sap. 



Absorption of gold from colloidal solutions by fungi, J.I. Williams {Ann. 

 Bot. [Lo7idon], 32 {1918), No. 128, pp. 531-534).— A study of Penicilliuni glau- 

 cum, O'idium lactis, and Aspergillus niger in a series of gold solutions, gum 

 arable being added as a nutrient, showed that conidia of P. gUmcnni and 0. lactis 

 can develop in a colloidal gold solution containing tannin or gum arable, the 

 growing fungus taking up the metal and retaining it in noncuticularized cell walls. 

 The process goes on more irregularly when masses of dead fungus are introduced. 

 Coloration of the fungus is more intense in solutions having a higher rate of 

 diffusion. In all cases a blue coloration finally results from the accumulation 

 of gold. 



Behavior of stomata, G. V. Loftfield {Carnegie Inst. Washington Year Boole, 

 11 {1918), pp. 289, 290). — The work here reported is said to be a continuation of 

 that done in the Selby smelter investigation, some accounts of which have been 

 previously noted (E. S. R., 37, p. 634). Forty species of crop plants have been 

 studied to determine the relation of stomata to the injurious action of smelter 

 fumes upon plant tissues. Similar studies were made at the Desert Laboratory 

 on several species of xerophytes and winter annuals. In addition, par- 

 ticular attention was paid to the relation of the stomatal opening to trans- 

 piration and to wilting. 



Results of the investigation seem to harmonize the diverging views as to 

 the regulatory action of stomata, since they not only show that species exhibit 

 extreme differences in the daily activity of their stomata but also that the 

 upper and lower epidermis of tlie same species may vary considerably. Prob- 

 ably the most important result noted is that all the species studied with 

 reference to wilting indicated that the stomata exercised a decisive regulatory 

 action at this time, even in the case of those most passive under less extreme 

 variations in the water relations. 



A contribution to the study of variations in respiration of plants as re- 

 lated to age, G. Nicolas {Rev. G&n. Bot., 30 {1918), No. 355, pp. 209-225).— 

 The author has followed up work previously noted ( E. S. R., 22, p. 327 ; 26, p. 

 628) \vith studies on different plants. He concludes that in the young organs, 

 principally the leaves, intracellular oxygenation is more complete than in older 

 organs. The younger tissues absorb much more oxygen than the more de- 

 veloped ones, while fixing relatively less, and thus set free larger quantities 

 of energy which are utilized in growth. 



Transpiration of trees, J. E. Weaver and A. Mogenson (Carnegie Inst. 

 Washington Year Book, 17 (1918), pp. 290, 291). — A comparative study of the 

 transpiration in coniferous and deciduous trees was carried on at the 

 I'niversity of Nebraska from September to May and at the Alpine Laboratory 

 (luring June and July. These studies, employing Pinus pondcrosa, P. banksiana, 

 Pscudotsuga nmoronata, Picea engelmannii, Abies grandis, Acer saccharinum. 



