430 EXPERIMENT STATION EECORD. 



pollen. There was found to be no essential difference whatever between the 

 pollen of the wild and domestic varieties, the normal shape of the dry potato 

 pollen being oval. Irregular grains are held to be either aborted or immature 

 and may be taken as a measure of the male sterility of the variety rather than 

 any indication of varietal or specific difference. The presence of irregular grains 

 In the seedlings of Solanum etuberostim is held to be no evidence for or against 

 this variety being the parent of the domestic potato. The absence of pollen in 

 the anther is dominant to its presence, and the characters absence and presence 

 of pollen segregate in subsequent generations. The number of living grains 

 in an anther is generally correlated with the total quantity of pollen present. 

 Pale heliotrope potato flowers were always found to be sterile, and, so far as 

 investigated, heterozygous as regards sterility. The later in the season the 

 flowers are examined the more likely is ithe character of the pollen to deterio- 

 rate. Sterility may arise suddenly in an individual member of a family possess- 

 ing a high degree of fertility. 



On right and left handedness in barley, R. H. Compton (Proc. Camhridge 

 Phil. Soc, 15 {1910), No. 6, pp. ^95-506, figs. 2). — In an examination of seed- 

 lings of barley, it was found that upon germination the first leaf in some cases 

 overlaps from the right to the left and in others in the opposite direction. 



This phenomenon has been studied in relation to inheritance, and the author 

 states that, so far as known, in random collections of barley seeds there will 

 be an excess of seedlings with the first leaf twisted in what may be called 

 the left-handed direction. The ratio of lefts to rights in the variety most 

 accurately studied was close to 1.5 : 1. So far as observed, the twist of the 

 last leaf below a spike was found to have no influence whatever on the ratio 

 of right-handed to left-handed seedlings produced from that spike. The same 

 ratio occurred among seedlings whether produced from the odd or even rows 

 of seed on the parent head, and no orderly arrangement of seedlings with re- 

 spect to twist in the first leaf could be detected on the head. The ratio among 

 seedlings in regard to characters of right-handedness and left-handedness 

 indicates that these are not hereditary. 



On the nitrogen supply of soils and of plants, with special reference to 

 nitrogen- fixing organisms, B. Heinze {Landiv. Mitt. Prov. SacJisen, 1910, 

 Nos. 15, pp. 57-59; IS, pp. 69-72; abs. in CentU. BaU. [etcl, 2. AM., 28 {1910), 

 No. 9-11, pp. 269, 270). — The author first considers the sources of nitrogen in 

 general, such as commercial fertilizers, nitrates already px'esent in the soil, 

 and the action of soil organisms in regard to nitrogen fixation, ammonification, 

 and nitrification. He then discusses more specifically (1) the influence of nitro- 

 gen-gathering soil organisms on the supply of available nitrogen in the soil, 

 including the root tubercles of legumes, the free living nitrogen fixing and 

 gathering soil organisms, such as ammonia formers, blue-green algte, species of 

 Azotobacter, and Streptothrix and Dematium species of soil fungi, and (2) the 

 conditions necessary for making available the soil and organic nitrogen pres- 

 ent, such as the addition to the soil of stable manure, soluble phosphoric acid, 

 and lime, thorough cultivation of the soil, high temperature, and a sufficient 

 amount of soil moisture. 



A contribution to the biochemistry of soils, R. Moll {Beitrdge sur Bio- 

 chemie des Bodens. Iruiug. Diss., Leipsic, 1909, pp. 5-^8; ais. in Jahres'ber. 

 Landic, 2Jf {1909), p. 41). — The author claims, as the result of his investiga- 

 tions, that the season of the year is the principal factor in determining the 

 biochemical behavior of soils in regai'd to peptone decomposition, nitrification, 

 nitrogen assimilation, and ammonia and nitrate fixation, and not the kind of 

 fertilizer used or even the weather conditions. 



