732 EXPERIMENT STATION EECORD. [Vol.43 



Some abnormalities in plant structure, M. S. Maukle (Proc. Ind. Acad. 

 ScL, 1918, pp. 117-12 ff, flys. 9). — Brief descriptions ure given of cell abnormali- 

 lios observed in plants named. 



Banding' and forking in roots, H. Sciiknck {Flora [Jena], n. ser., 11-12 

 (J!) IS), pp. 503-525, figs. 10). — Kxiunples cited are taken to indicate that, in 

 connection with most plant organs or parts, roots lack definiteness and fixity 

 of form when tested under unusual conditions as regards environment. 



Anatomical modifications of roots by mechanical action, E. Blocii 

 (Compt. Raid. Acad. Sci. [Paris], 169 (1919), No. 4,' pp. i95-i97).— Studies 

 briefly described as carried out with plants named show that it is possible 

 to reproduce experimentally not only certain asymmetric structures observed 

 in plants as occasionally subject to unusual natural stresses, but also anatomical 

 modifications resulting in certain cases from the influence of the medium. 



Wound cork formation in the potato in relation to seed piece decay, 

 M. Shapovalov and H. A. Edson {Phytopatholooy, 9 {1919), No. 11, pp. J,83-Jt9G, 

 figs. 3). — Experiments are reported in which Irish Cobbler, Green Mountain, 

 and Bliss Triumph potatoes were investigated to determine whether the sprout- 

 ing of the tuber, dusting it with sulphur, or entrance of decay has any bearing 

 on the formation of wound cork. 



It was found that sprouting did not affect the ability of the potato to form 

 wound corlf over a wound surface, but drying of the tissues, as when potatoes 

 were stored in a warm room, checked this ability. Sulphuf applied to cut seed 

 pieces was neither beneficial nor detrimental to cork formation. The presence 

 of decay in the central surface of the cut seed pieces appeared to be correlated 

 with the healing proclivity of the centi-al portion as compared with that of the 

 more resistant peripheral areas. The resistance of the seed piece to attacks 

 was found to diminish in direct proportion to the water loss, and a shriveled 

 tuber is unable to initiate cell division until it has imbibed the necessary amount 

 of moisture from the soil. Consequently destructive activities of microorganisms 

 develop so rapidly that the formation of the protective layer under the infected 

 lesions is often checked and the seed piece fails to grow entirely or produces 

 only feeble shoots. 



Root cork in plants of highly heated soils, L. Diels {Flora [-Jena], n. ser., 

 11-12 {1918), pp. It90-502, figs. S). — Notes are given of a partial study of the 

 ecological significance of root cork of plants under certain trying conditions as 

 regards environment. 



The penetrability of foliage leaves for gases, F. W. Neger {Flora [Jena], 

 n. ser., 11-12 {1918), pp. 152-161 figs. 3). — Placing leaves in one or the other of 

 the two classes homobaric or heterobaric according as they possess compara- 

 tively free or practically no communication between their intrafoliar spaces, 

 the author lists as homobaric all conifers and some other plants and as hetero- 

 baric a number of other plants. The significance of the two plans is discussed. 



Kerosene injury to shade trees, R. E. Stone {Phytopathology, 9 {1919), 

 No. 10, pp. 476, -^77). — An examination was made of a number of shade trees, 

 particularly maple, which had died, and it was found that the bark, cambium, 

 and sap wood had been killed in a zone 3 in. wide at a height of about 4 ft. 

 from the ground. An investigation showed that about tliree years before the 

 appearance of the disease the trees were banded with cotton wool soaked in 

 kerosene to prevent the climbing of tussock moths. The excess of kerosene was 

 allowed to run down the trunk, and from the form and position of the dead 

 areas it is considered that kerosene had been the destructive agent. 



The influence of winter weather on forest trees, H. Hofker {Mitt. Dcxit. 

 Dendrol. Gesell., 28 {1919), pp. 196-207).— An account is given wdth discussion 



