130 EXPERIMENT STATION RECORD. [Vol.43 



The various genera of Cyperacere are considered in order, but cluef atten- 

 tion is given to Carex, witli a statement of the association types in whicli 

 species of this genus are prominent. The several associations belonging- to 

 these types are characterized as to ecological relations and floristic compo- 

 sition. It is pointed out that most sedges belong to the early stages of suc- 

 cession in the vegetation of a region. A list iS' given of 44 species of Carex, 

 of which 20 are classed as water and marsh plants, 9 as species of meadow or 

 other mesophytic situation, and 15 as species of xerophytic habitats. 



The ecologic subterranean anatomy of some plants of a prairie province 

 in central Iowa, A. Hayden {Adici: Jour. Bof., 6 (1919), No. 3, pp. S7-105, pU. 

 IJf). — A study of the minute anatomy of the subterranean oi-gans of prairie 

 plants as here outlined is said to show that, there is a tendency to the produc- 

 tion of prominent mechanical tissue in plants of dry habitats and to the 

 reduction of parenchymatous tissue, though the latter is prominent in plants 

 of moist habitats, while aerenchynia is notable in plants of swamp habitat. 

 The vascular tissue is variable in quantity, seemingly more- or less subject to 

 systematic variation. The subterranean stem is predominant as an equiva- 

 lant of the primary root, especially in moist lowland regions. It is more ef- 

 ficient than the root in propagation. Primary roots which show secondary 

 thickening resemble stems in their concentric manner of expansion. The stem 

 has an area of iiith, which serves as a reservoir for water and hence increases 

 its efficiency for radial distribution. 



Some observations on the tuber of Phylloglossum, T. G. B. Osborn {Ann. 

 Bot. [London^, S3 (1919), No. 132, pp. J^85-516, pi. 1, figs. 43).— A new method 

 of vegetative reproduction is noted for P. drutmnondii, which occurs in South 

 Australia as a member of the geophytic element in the flora of an area subject 

 to prolonged summer desiccation. An adaptive variation in the length of the 

 tuber stalk tends to locate the tuber at a depth of about 1 cm. The new 

 method consists in regeneration from leaves which have been injured or de- 

 tached. This method is described with discussion. 



The sprouting of woody plants and the influence of external factors 

 thereon, O. KtiiiN (JaJirh. Wlss. Bot. [Pringsheim'i, 57 (1916), No. 1, pp. 1- 

 16, figs. 5). — Light and the presence of nutritive salts influenced the sprouting 

 of woody plahts which, however, has no necessaiy connection with the rest 

 period. 



Viability of cletachefl root-cap cells, L. Knudson (Amer. Jour. Bot., 6 

 (1919), No. 7, pp. 309, 5i0).— Having noted and tested the viability of detached 

 root-cap cells, the author gives accounts of the survival of such cells f(U' 

 71 days. 



Studies on growth and change of form in vegetating points, O. Schuepp 

 (Jahrb. Wiss. Bot. [Pringsheim], 57 (1916), No. 1, lyp. 17-79, figs. 16).— The 

 investigations here noted are considered to support the view that a slinuilus 

 from the surface leads to the arrangement of the meristemic cells parallel to 

 the surface and to consequent flatness of the layer. Failure of such stimulus 

 may lead to unregulated growth and an anomalous thickness. 



The periodic differentiation of the growing point is primary, following, how- 

 ever, a continued stimulation from the surface affecting the meristemic cells. 



A study of some factors in the chemical stimulation of the growth of 

 Aspergillus niger, II. A. Steinberg (Atner. Jour. Bot., 6 (1919), Nos. 8, pp. 

 330-356, figs. 2; 9, pp. 357-372).— It is stated that increased acidity of the 

 Pfeffer nutrient solution Avithin limits produces in A. niger a groAvth stimula- 

 tion similar to that obtained by adding salts of certain heavy metals, but less 

 in amount, the appearance of the cultures being the same in some respects as 



