820 EXPERIMENT STATION RECORD. [Vol.35 



failure in attempts to cross the annual homostyled Linum usitatissimum with 

 some such heterostyled species as L. perenne. He states, as a result of ex- 

 perimentation briefly noted, that the raising of a tall strain of flax is a very 

 easy matter and can be done by selection of materials already existing in com- 

 mon crops. It is thought that most seed produced under natural conditions 

 results from self-fertilization. 



It is thought by the author that besides the oil flaxes, which are about 1.75 

 ft. in height, there are in England pure types of at least three other heights, 

 the native tall strain measuring about 4 ft., several ordinary blue, and also some 

 white, forms about 3 ft. high, and a dark blue true-breeding type about 2.5 ft. 

 in height. 



The ecological histology of prairie plants, Ella Shimek (Proc. Iowa Acad. 

 ScL, 22 {1915), pp. 121-126, pi. 1). — The material for this investigation, which 

 is hex'e only partially reported but which is intended to ascertain the character 

 of the various structural adaptations to environment made by ordinary plants 

 in Iowa, includes 65 of the 271 species characteristic of the prairies. It is 

 stated that the flora of the prairie is essentially xerophytic, differing from 

 desert flora chiefly in the degree of modification for protective purposes. The 

 xerophytic adaptations vary in different species as do the xerophytes of the 

 desert, though usually in smaller degree. 



On the behavior of an excised branch of the Sahuaro, R. J. Pool {Plant 

 World, 19 {1916), No. 1, pp. 17-22, fig. 1).—A brancli of the giant cactus {Car- 

 negiea gigantea), having been removed from Tucson, Ariz., to Lincoln, Nebr., 

 produced several flowers in 1914 and a much greater number in 1915, but no 

 fruits were produced from any of these flowers. A second specimen treated in 

 like manner produced neither flowers nor fruits in 1915. 



On the association and possible identity of root-forming and geotropic 

 substances or hormones in Bryophyllum calycinum, J. Loeb {Science, n. ser., 

 44 {1916), No. 1128, pp. 210, 211). — An account is given of recent experiments 

 which led the author to conclude that the substances responsible for root for- 

 mation in the stem of B. calycinum are associated or possibly identical with 

 the substances causing geotropic curvatures of the stem of this plant. This 

 close association or identity of organ-forming and geotropic substances, it is 

 thought, might also explain the regeneration that takes place in certain conif- 

 erous trees when the uppermost horizontal branch begins to grow vertically if 

 the apex is cut off. 



Do fungi live and prodtice mycelium in the soil? S. A. Waksman {Science. 

 n. ser., U {1916), No. 1131, pp. 320-322).— By a method of incubation for a com- 

 paratively short period, the author has found evidence indicating that a num- 

 ber of organisms form mycelium in the soil. About 15 species were found more 

 or less commonly in soils of different types and from different localities, 

 Mucor circinclloides, Zygorhynchus vuilleminii, a green Trichoderma, RliizopuH 

 nigricans, and M. racemosus being found most abundantly. The Zygorhynchus 

 was the only organism isolated at depths of from 12 to 30 in. A number of 

 other organisms were only rarely found, which are quite usually found present 

 by the dilution method of plating. Organisms such as species of Aspergillus, 

 Alternaria, Cladosporium, and most species of Penicillium did not appear on 

 the plates within 24 hours when the soil had been inoculated directly upon 

 sterile medium. 



The red color of the mesocarp of seeded fruits in the persimmon (Diospyros 

 kaki). A visual method for estimating astringency, F. E. Lloyd {Plant 

 World, 19 {1916), No. 4, pp. 106-113, fig. 1).—It is stated by the author that in 

 persimmons of the race Zengi, studied by him, the region of nonastringency is 

 not coextensive with that of the red colored tissues. From this It is inferred 



