19171 AGRICULTURAL BOTANY. 826 



decided influence on the development of tlie fruit. In legumes the growth of 

 each seed influences the development of the corresponding portion of the fruit. 

 The transfer of food from stem to seeds begins after the processes which deter- 

 mine seed shape have been completed. 



Under the influence of a humid atmosphere the yield of cereals was reduced 

 while that of peas was increased, the ash content of peas and wheat was in- 

 creased while that of oats was lowered, albuminoid substances were increased 

 in all seeds, and the oil content of flax was slightly diminished. Shading low- 

 ered the yield of oats and peas but that of wheat was somewhat increased. 

 The ash content was generally increased, as was also the albuminods in peas 

 and wheat. Slight shading resulted in an increase in the starch content of 

 seeds, while the oil content of flax was lowered. The quality of the oil was not 

 influenced by slight shading, but with heavy shade the iodin number was below 

 normal. 



A resting period for a variety of durum wheat was found to be unnecessary 

 as the seed would readily germinate before complete maturity. 



The formation of auximones from^ nitrogenous organic substances, W. B. 

 BoTTOMLEY (Abs. in Rpt. Brit. Assoc. Adv. Sci., 85 {1915), pp. 728, 729).— A 

 method for investigating the presence of auximones has been developed in 

 consequence of the observation that on crude nitrifying culture solutions con- 

 taining these substances, a bacterial scum is formed. It has been found that 

 during the germination of seeds, auximones are formed, and that they enable 

 the embryo to utilize the food materials in the seed. Auximones are formetl 

 during the humification of nitrogenous organic matter, and the amount of 

 auximones present depends upon the extent of humiflcation. Fresh manure, 

 rotted manure, and bacterized peat have been found to contain auximones in 

 the proportion of 1:5: 250. Experiments carried out as described, on Lemna 

 minor growing in Detmer's culture solution, are considered to show that the 

 purer auximone silver fraction is more effective on growth than the cruder 

 phosphotungstic fraction. 



The location of spore masses in the Uredineee and its value as a character 

 in classification, F. Grebelsky {Centbl. Bakt. [etc.], 2. Abt., 43 {1915), No. 25, 

 pp. 6^5-662, figs. 12). — Concluding a study of several species, mainly of Puc- 

 cinia and Uromyces, on various hosts named, the author states that a close and 

 almost universal relation may be asserted between the position of the spore 

 masses and that of the stomata as dorsal or ventral in case of the uredospores. 

 The same is true in a considerable degree in case of the teleutospores. 



The position of the spore masses can not, then, be regarded as a systematic 

 character unless it be indirectly, in so far as choice of host is a species char- 

 acter, certain species living on hosts which have stomata on the one or the 

 other leaf surface. For some other species the position of the teleutospores is 

 characteristically independent of that of the stomata. It is, therefore, neces- 

 sary to know the degree of dependence or independence in this respect in em- 

 ploying the position of spore masses as a species character. As regards those 

 cases where the spore masses lie beneath the stomata, further investigation is 

 required regarding the part played by the influence of negative hydrotropism 

 and the advantages of access to oxygen. 



Studies on the succession and ecology of epiphytic bryophytes on the bark 

 of common trees in Denmark, C. Olsen (Bot. Tidsskr., 34 (1917), No. 7, pp. 

 S1S-S42, figs. 4). — The author reports that epiphytic bryophytes are always 

 found in woods on one side of the tree stem and not on the other. This is 

 accounted for by the fact that most forest trees deviate from the perpendicular 

 more or less, and it is on the upper sides of such trunks that the mosses are 



