BOTANY. 205 



Studies in nuclear phenomena and the development of the ascospores in 

 certain Pyrenomycetes, ^I. A. NiciKtL.s (Presenlcd be/ore. Sec (i of Ihe American 

 Aa-socialion for the Advanceineut of Science, Aiuj., ISOr,; ahs. in Science, n. ser., 4 {1S90), 

 No. 01, pp. 430, 431). — As a result of these studies, it is shown that sexual processes 

 may bo present in some and absent or dcgeuerate in other members of the Sphieria- 

 cea'. An account was also given of the discovery of nuclei in this family, their 

 structure and behavior during division. 



On the formation and distribution of abnormal resin ducts in conifers, A. P. 

 Andeksox (Presented before Sec. G of the American Association for the Advancement of 

 Science, An;/., 1S96; abs. in Science, n. ser., 4 {ISOG), Xo. 91, pp. 431, 43.2). — Notes are 

 given on the influence of frost, fungus attacks, etc., upon the formation and dis- 

 tribution of resin ducts in Finns sylreslris, P. strobus, Plcea excel. sa, and Abies pectinata. 



The curvature of tendrils, D. T. MacDougal (Presented before Sec. Gof the Ameri- 

 can Association for ihe Advancement of Science, Aug., 1S9G; abs. in Science, n. ser. ,4(1896) 

 No. 91, p. 43~>). — It is stated that curvature in response to a stimulus is due to the 

 contraction of certain cells on the concave side of the tendrils. It was found that 

 the effects of the stimulus were not transmitted more than 2 cm. from the point of 

 reception. 



The influence of rainfall upon leaves, U. T. MacDougai, (Presented before Sec. G 

 of the American Association for the Advancement of Science, Aug., 1S9G; abs. in Science, 

 n. ser. ,4 (1S96), No. 91, p. 43'>). — The investigations of Ridley and .Stalil are mentioned 

 and a brief resume is given of the observations of Junger in the same line. 



The forces determining the position of leaves, E. N. Day (Presented before See. 

 G of the American Association for the Advancement of Science, Aug., 1896; abs. in Science, 

 n. ser., 4 (1S9G), No. 91, p. 430). — Specimens of Phaseolus, Taraxacum, Cucurbita, 

 Nicotiana, Helianthus, and Arissema were grown in light and darkness in upright, 

 horizontal, inverted, and planostat positions, and the author concludes that the 

 heliotropic tendency of leaves so far overbalances the other influences as to determine 

 their position; hence it is a physiological and not a mechanical resultant. 



Rheotropism and the relation of re.sponse to stimulus, F. C. Newcombe (Pre- 

 sented before Sec. G of tlie American Association for the Advancement of Science, Aug., 

 1896; abs. in Science, n. ser., 4 (1806), No. 91, p. 43.3).— The effect of flowing water as 

 a stimulus is mentioned, those roots curving against the stream being called posi- 

 tively and those with the stream negatively rheotropic. The roots of many plants 

 were shown to be positively rheotropic, while others are unresponsive. The stimulus 

 is not considered as necessarily closely biological, but may be mechanical. 



The graft from antiquity to the present time, L. Daniel (Le Monde des Pluntes, 

 ser. 2, 5 (ISOG), pp. 73, 89, 106, 113). 



On the supposed immediate effect of pollen, H. J. Webber (Science, n. ser., 4 

 (1896), No. 93, pp. 498-500). — The author believes reversion and graft hybridization 

 more responsible for unusual forms of fruit than the immediate efl'ect of a foreign 

 pollen. 



Grass flora of Iowa, L. H. Pa:\imel (Presented before Sec. (r of the American Asso- 

 ciation for the Advancement of Science, Aug., ISOG ; abs. in Science, u. ser., 4 (1896), No. 

 91, p. 433).— 'Sotcs were given of the indigenous grasses of the State, their distribu- 

 tion and relative value. 



The distribution of the species of Gymnosporangium in the South, L. M. 

 Underwood and F. S. P2arle (Presented before Sec. G of the American Association for 

 the Advancement of Science, Aug., 1806 ; abs. in Science, n. ser., 4 (1896), No. 91, p. 437). — 

 The distribution of the 6 species parasitic on Juniperus rirginiana is given, the most 

 common ones being Gytnnonporavgium macropnx, G, clavipes, and an nndescribed 

 species. 



Formaldehyde as a preservative of vegetable tissues, .1. 1.'. .Iacksox (Gard. 

 Chron., ser, 3, 30 (1896), No, 500, p. 365). 



