lyiO] AGRICULTURAli BOTANY. 8J 9 



I>. 328) and (lescribinj; later observations on the absorption of nutriment throu^'h 

 aerial portions by the mulberry, the author concludes that in very small 

 plants glucose solution produces distinct acceleration, the development including 

 also morphological variations internally and externally. In somewhat older 

 plants the differences produced are less striking, but are still distinct. In 

 still older plants the differences produced are very slight. These observations 

 are said to agree with those of Molliai'd (E. S. R., 35, p. 633) regarding the 

 morphogenetic influence of sugar. 



Behavior of plants in unventilated chambers, F. C. Newcombe {Ann. Rpt. 

 Midi. Acad. Sci., 20 (WIS), pp. 14-5, 14^). — During three years, laboratory tests 

 have been made giving data bearing on the hypothesis that plants thrive best 

 when well ventilated. The results of three series of experiments are given, 

 leading to the conclusion that plants are not materially benefited by ventila- 

 tion. 



[The relations between temperature and the seasonal progress of vegeta- 

 tion], G. RiTTER (Bnt. Centbl., Beihefte, 35 (1911), 2. AM., No. 2-3, pp. 568- 

 577, fig. 1). — The author gives data obtained from observations on seasonal be- 

 havior of a number of plants in the vicinity of Bremen in regard to such 

 phenomena as the appearance of blooms, leaves, ripe fruits, leaf coloration, 

 and leaf fall. A study of correlations is considered to indicate a close cor- 

 respondence between these phenomena and those of climate and of weather, 

 more particularly during the earlier part of the growing season. 



Demonstration of methods for the study of stomatal action, M. Pengelly 

 (Ann. Rpt. Mich. Acad. ScL, 20 (1918), p. 154).— These methods were related to 

 work employing, respectively, Darwin's porometer, the hygrometric paper tests, 

 and direct examination with the microscope. 



Conductivity as a, measure of permeability, W. J. V. Osteehout (Jour. Biol. 

 Clieni., 38 (1918), No. 3, pp. 485-487).— A study of a green alga (Ulva) and of 

 a marine flowering plant (Zostei'a), both of which have cellulose wails, by 

 the electrical conductivity method is said to show that this method measures 

 permeability just as other methods do, but that the method herein used is more 

 accurate and more convenient. This makes it possible to determine conductivity 

 at shorter intervals, thereby detecting any rapid clianges which may occur and 

 determining the time curve with greater precision than is otherwise possible. 



Note on the effect of diffusion upon the conductivity of living tissue, 

 W. J. V. Osterhout (Jour. Biol. Chem., 36 (1918), No. 3, pp. 489, ^90).— Having 

 noted exceptions to the rule that electrolytes produce in living tissues either 

 a rise in resistance followed by a fall, or merely a decrease in resistance, the 

 author describes a case in which the effects noted are ascribed to diffusion. 



A method of measuring the electrical conductivity of living tissues, 

 W. .T. V. Ostekhout (Jour. Biol. Chem., 36 (1918), No. 3, pp. 557-568, figs. 8).— 

 The author gives an account of a method employed in studies such as those 

 above noted to determine the electrical conductivity of living tissues of 

 organisms, claiming that under favorable conditions the results do not vary 

 more than 1 per cent from the mean of the measurements. 



A comparative study of permeability in plants, W. J. V. Osterhout (Jour. 

 Gen. Physiol., 1 (1919), No. 3, pp. 299-304, figs. 2).— Studies measuring perme- 

 ability (as in those above noted) which were carried out with a brown alga 

 (Larainaria), a green alga (Ulva), a red alga (Rhodymenia), and a flower- 

 ing plant (Zostera), are said to have shown essential similarity in respect 

 to the changes in permeability occurring in these plants. 



The relation between the structures of some coniferous woods and their 

 penetration by preservatives, P. C. Kitchin (Atm. Rpt. Mich. Acad. Sci., 20 

 (1918), pp. 203-221, pis. 2).— This work, suggested by one of the conclusions 



