432 BOTANICAL GAZETTE [ DECEMBER 
botany which may have given suggestions as to possible relationships. In 
other words, he has abandoned the customary morphological method and has 
called to his aid anatomy, embryology, physiology, “ biology,” and plant 
geography, He regards the Polycarpicae (Ranunculaceae, ef a/.) as the most 
primitive angiosperms, from which have come all other dicotyledons (espe- 
cially Amentiferae and Sympetalae) on the one hand, and the monocotyle- 
dons on the other. He also thinks that the Convolvulaceae are not to be 
associated among the Tubiflorae, but are related to the Sapotaceae, Malva- 
ceae, etc., and belong to the Ebenales which originated in the neighbor- 
hood of the Anonaceae. A great number of families and alliances are shifted 
in this way, the details being too numerous to be given in this notice, need- » 
ing full presentation to be appreciated.—J. M. C 
THE ADDRESS of Dr. B. L. Robinson as retiring” president of the Botanical 
Society of America, entitled “Problems and possibilities of systematic 
botany,” and delivered last August at the Denver meeting, has now been 
issued as a publication (no. 18) of the Society. The author's summary is as 
follows: ‘It may be said that systematic botany is very far from being a 
completed subject, that from our present standpoint we can see in various 
directions long vistas of further possibilities for fascinating explorations and 
profitable discovery, that among the subjects which seem to invite immediate 
attention the most important are: (1) The determination of the modes and 
degrees of variation, an investigation which alone can yield data for a more 
critical discrimination of plant categories; (2) far more complete study of 
plant ranges, which can scarcely fail to throw much new light upon the forces 
controlling distribution ; and (3) a further examination of plant ontogeny as 
the most hopeful source of information regarding the more intimate affinities 
and proper arrangement of plants.”"—J. M. C 
GIESENHAGEN ” reports some observations made by him in 189I-2 upon 
the growth of the rhizoids of Chara, which seem to confirm the recent 
theories and observations of Haberlandt, Noll, and Némec, on the perceptive 
organs for geotropic stimuli. When young rhizoids of Chara were directed 
upward there was first a retardation of their growth, with subsequent recovery 
of the previous rate, and soon a curvature which directed the tip of the 
rhizoid again downward. Similar retardation followed the placing of the 
young rhizoid in a horizontal position and a downward curvature also 
occurred. Near the tip of the rhizoid Giesenhagen found a group of small 
granules which altered their position when the rhizoids were displaced, The 
change in the position of these relative to the sensitive cytoplasm, he regards 
as producing the immediate stimulation from which curvature results. The 
nature of these minute granules has not been ascertained, but in this terminal 
7 Ber. deutsch. bot. Gesell. 19: 277-285. f/. 72. 1901. 
