304 BOTANICAL GAZETTE [NOVEMBER 
CLEMENTS*° has given a short account of formation and succession herbaria. 
The idea of herbaria based on habitats in addition to those based on taxonomic’ 
characters seems to have been suggested by Drupg, and has now been followed 
out in several places. No one has worked out the idea more systematically than 
has CLEMENTS in the Colorado mountains, and he distributed herbaria from 
there in rgor. Succession herbaria illustrate the dynamics of plant formations, 
and are the most desirable of ecological herbaria, but the most difficult to prepare. 
In his Colorado work the cryptogams, apart from the ferns, have been incorpo- 
rated into a separate herbarium. The paper closes with an illustrated list of 
Colorado plants arranged by formations; in each formation there appears first the 
facies, followed by the principal and secondary species of the spring, summer, and 
autumn aspects.—H. C. Cow es. 
Kister+! takes issue with SENN, who in a recent preliminary report has 
concluded that the position of chloroplasts in darkness is to be accounted for by 
an uneven distribution of the substance chemotactically potent upon them. The 
author’s experiments with Dictyota and Padina especially, show that under the 
influence of hypertonic solutions the chloroplasts arrange themselves along the 
side walls (Profilstellung), while hypotonic solutions cause them to seek the uppet 
and lower walls (Fidchenstellung). The change in turgor pressure of the cell B 
thus the direct cause of orientation movements of the chromatophores and this 
change may be induced by light, or by hyper- or hypotonic solutions independ- 
ently of light—Raymonp H. Ponp. : 
Miss LatHam,4? Barnard College, in investigating the response of fungl 
to the vapor of chloroform, has reached the following conclusions: (1) _— 
present in small quantities chloroform vapor acts as a characteristic stimulant 
to the growth of Sterigmatocystis nigra and Penicillium glaucum; (2) larger 
quantities are inimical or fatal; (3) increased growth is attended by relatively 
less acid formation and less sugar consumption, indicating greater gue is 
metabolism; (4) the time of greatest sensitiveness is at the germination of 
spores; (5) chloroform acts as a stimulant purely, since it cannot be a a 
of carbon; (6) the effect of a given amount of the anaesthetic is greater as 
temperature rises.—J. M. C. eS | 
DarpisuiRess has undertaken a study of Mamillaria, especially with av" 
to interpreting the significance of the plant form and the spines. ee: 
4° CLEMENTS, F. E., Formation and succession herbaria. University of Nebrask# 
Studies 4: no. 4. pp. 27. 1904. 
41 Kuster, E., Ueber den Einfluss von Lésungen verschieden 
auf die Orientierungsbewegungen der Chromatophoren. Ber. Deuts 
23:254-256. 1905. 
42 LATHAM, MARION ELIZABETH, Stimulation of Sterigmatocystis by — 
Bull. Torr. Bot. Club 32:337-351. 1905. Annals of Bot 
43 DARBISHIRE, O. V., Observations on Mamillaria elongata. 
18:375-416. 1904. 
er Konzentration 
ch. Bot. Gesells 
