198 PATHOLOGY [BoT. Absts., Vol. VIII, 



In those yielding growth, many organisms were found: Species of Fusarium, 720 times; 

 AUernaria, 615 times; bacteria, 241 times; Verticillium, 147 times; Penicillium, 104 times; 

 Colletotrichum, 91 times; Rhizoctonia, 12 times; miscellaneous, 87 times.— Field trials in Colo- 

 rado with tubers from widely separated sources indicate that neither vascular discoloration 

 nor fungous invasion of the tissues of the mother tuher is a guaranty of disease in the result- 

 ing plants; nor is their absence a guaranty of health. The soil and not the tuber is the more 

 potent source of disease.— Stem-end pieces used for planting yielded slightly higher percent- 

 ages of diseased plants than did eye-end pieces. Plants showed a marked capacity for recu- 

 peration, which varied with the variety, environment, and with the interaction of the two. — 

 D. Reddick. 



1372. Fracker, S. B. Varietal susceptibility to false blossom in cranberries. Phyto- 

 path. 10: 173-175. 1920.— A tabular presentation and brief discussion of varietal suscepti- 

 bility. The cultural conditions are given, together with inspection practices and control 

 measures. — R. B. Streets. 



1373. GuYTON, T. L. The chrysanthemum gall midge. Ohio Agric. Exp. Sta. Bull. 341. 

 lOS-114, 6 fig. 1920. 



1374. Hahn, Glenn G., Carl Hartley, and Arthur S. Rhodes. Hypertrophied len- 

 ticels in the roots of conifers and their relation to moisture and aeration. Jour. Agric. Res. 20: 

 253-265. PI. U-46. 1920 [1921].— Unusual excrescences on the roots of 10 species of Pinus, 

 4 of Picea, and of Abies balsamea, Tsuga canadensis, Larix laricina, Taxus cuspidata, T. 

 brevifolia, and Araucaria bidwellii, are found to have the structure of lenticels, much en- 

 larged. They occur and were produced in various kinds of soil in the presence of excessive 

 soil moisture. Hypertrophy occurs on both weak and vigorous plants. It is decreased by 

 top pruning and is increased by root injury.— The literature is reviewed. The belief that 

 excessive soil moisture stimulates lenticel hypertrophy mainly by increasing general sap 

 pressure, and that oxygen hunger is of no importance as a stimulus, is not supported by 

 these experiments. A bibliography of 23 titles is appended.— D. Reddick. 



1375. HuRD, Annie May. Injury to seed wheat resulting from drying after disinfection 

 with formaldehyde. Jour. Agric. Res. 20:209-244. PL 36-41. 1920 [1921].— Results of 

 investigations on the post-treatment action of formaldehyde on wheat are recorded. The 

 major conclusion reached is that injury results from the drying of grain treated with formal- 

 dehyde solution; that seed wheat is uninjured by a 0.1 per cent solution (1-40) and, if kept 

 moist, may be held indefinitely without injury unless attacked by molds. Neither a 0.1 

 per cent (1-40) nor a 0.2 per cent (1-20) solution of formaldehyde produces injury if the wheat 

 is germinated immediately. Injury to dried grain is cumulative. Paraformaldehyde is 

 deposited on dried grain, and the gas formed by the volatilization of this solid penetrates 

 the wheat slowly, probably going into solution in the pericarp. The manner of drying and 

 the moisture content of the atmosphere surrounding the grain determine the nature and 

 extent of injury. An atmospheric humidity of over 70 per cent during the storage period 

 prevents injury; one of 70 per cent or less permits injury, which is most severe in the inter- 

 mediate humidities, gradually decreasing in the lower ones. Treated grain stored in an 

 absolutely dry chamber is almost uninjured. It is considered probable that the formalde- 

 hyde does not enter the wheat as a gas or in the solid polymeric form, but in solution in the 

 seed coats. An optimum atmospheric humidity to permit, first, the formation of parafor- 

 maldehyde, and, second, the solution of formaldehyde gas in the grain, results in maximum 

 injury from drying after treatment. Injury is minimized by spreading the wheat as it dries 

 so that maximum aeration occurs. Washing the grain with water immediately after treat- 

 ment entirely prevents post- treatment injury from dry storage.— L. M. Massey. 



1376. Kelley, W. p., and A. B. Cummings. Composition of normal and mottled citrus 

 leaves. Jour. Agric. Res. 20: 161-191. 1920 [1921].— Lemon, orange, and grapefruit leaves 

 are similar in composition. As growth of normal orange leaves proceeds the percentages of 



