1917] AGRICULTURAL BOTANY. 327 



activities of different parts iu tlie potato, tulip tree, and sugar beet. Tlie 

 onion showed no oxidase activity iu eitlier leaves or roots, and the graphs for 

 these parts in spinach were entirely at variance, so far as appearances indi- 

 cate. Each plant apparently has its characteristic relationships. 



The results of this work are considered to indicate that tlie capacity of the 

 plant to oxidize the various compounds employed is characteristic of the par- 

 ticular plant, but that it varies in intensity, and in this respect only, in the 

 different parts of the same plant, showing a distinct and characteristic type 

 of metabolism for each plant. It remains to be investigated to what extent 

 plants of the same genus or species resemble each other in their metabolism. 



A comparative study of winter and summer leaves of various herbs, J. P. 

 Stodek {Bot. Gas., 63 (WIT), No. 2, pp. S9-i 09). —Summarizing the findings and 

 conclusions of a study carried out with numerous plants collected near Chicago 

 or in eastern Pennsylvania, the author states that typical rosette leaves in 

 shaded and protected situations are on the whole decidedly more mesophytic 

 than are stem leaves, which are exceeded as regards xerophytism by winter 

 leaves on stolons or runners. 



liocal and temporary autumnal symbiosis, L. Montemartini {Separate from 

 Atti 1st. Bot. R. Univ. Pama, 2. ser., 11 [1916^, pp. 7). — The author, having 

 observed cases in which the portions of leaves of Acer platanoides which were 

 parasitized by Unciniila aceris remained green while other parts went through 

 the regular autumnal changes, and cases of similar behavior in Corylus avel- 

 lana attacked by Phi/llactinia sufjulta, has made a study of maple leaves during 

 a period nearly coincident with the first half of November. 



It was found that the dry matter of the leaf was greater in the parasitized 

 areas than outside them during this period, especially during the middle 

 portion. The ratio of ash content to dry substances was somewhat less during 

 that period in both green and yellow portions of the leaves. From these and 

 other facts it is concluded that these cases may represent a temporary sym- 

 biosis, due to a diminution of virulence of the parasite and to a variation in 

 the resistance of the liost during this period owing to the effects of external 

 conditions then prevalent. 



The penetration of foreign substances introduced into trees, W. H. Rankin 

 (Fhytopathology, 7 (1911), No. 1, pp. 5-13, fig. 1). — Experiments are reported 

 upon in which chestnut trees from 2.5 to 9 in. in diameter were fed solutions 

 of lithium nitrate, a modification of the Shevyrev method being employed 

 (E. S. R., 15, p. 60). 



An examination of cross sections of the trunks of the trees showed that 

 lithium nitrate, under the method employed, penetrates to all places in the 

 tree where there is active translocation of food materials ; that is, to all parts 

 of the bark and sapwood above and below the point of feeding. Complete 

 penetration of the heartwood was obtained in trees of less than 3 in. in 

 diameter. In trees of greater diameter the process of penetration was slow and 

 did not seemingly follow any definite rule. 



The injurious effects of tarvia fumes on vegetation, A. H. Chivkrs (Phyto- 

 pathology, 7 (1911), No. 1, pp. 32-36). — Following up observations of the effect 

 of tarvia fumes on growing plants where at least 20 species and many varieties 

 were injuriously affected (E. S. R., 35, p. 784), the author presents data secured 

 from laboratory investigations which confirm the previous conclusions. 



Experiments conducted under controlled conditions showed that the injury 

 was due in large part to the volatile substances, which condensed in the form 

 of an oily coating on the surfaces of the plants. The injury is considered 

 due to the action of fumes on the aerial parts of plants, its amuunt varying 



