March 31, 1905.] 



SCIENCE. 



499 



logical Society, into a national Botanical 

 Society. A committee, consisting of the 

 present and retiring presidents and the 

 secretary, Avas appointed to cooperate with 

 committees of the other societies to take 

 further steps towards bringing the union 

 into effect. The society expressed by 

 special vote its great appreciation of the 

 hospitality of the university during the 

 iiii^eting, and its sineei'e thanks therefor. 



The address of the president dealt with 

 'Applied Botany and its Dependence upon 

 Scientific Research.' It has been printed 

 in full in this journal. The papers, of 

 which abstracts follow, were with but two 

 exceptions presented in full and discussed, 

 and include all that were admitted to the 

 program. The abstracts are in every case 

 by the authors. 



Causes Inducing the Hahit of Growth of 



Asparagus plumosus: Professor F. C. 



Newcombe, University of Michigan. 



The common asparagus fern so-called is 

 grown as a dwarf or as a climbing plant, 

 according to the space afforded the roots. 

 It bears no functional leaves, but th'^ work 

 of carbon assimilation is performed by the 

 branches, the ultimate ones of which occur 

 in little tufts of needles. The remarkable 

 thing about the habit of growth ( f the 

 plant is its change from a radial struetiire 

 to a dorsiventral, and a rather sudden 

 change in its response to environment. 



The young main stems of the plant are at 

 first erect, positively heliotropic and nega- 

 tively geotropic. At the time the second- 

 ary branches begin to grow out, however, 

 in the dwarf plants the upper part of the 

 main stem, or in the climbing plants the 

 oldest lateral branch, assumes the hori- 

 zontal position, and all members which 

 subsequently grow from this horizontal 

 piece take the horizontal position. This 

 change to the horizontal position is made 

 in the course of three to four days. It 



may be considered as due to the plant be- 

 coming diaheliotropic, or diageotropic, or 

 the position may be the resultant of the 

 antagonistic action of negative heliotropism 

 and negative geotropism. 



Experiments have shown that the hori- 

 zontal position is the result of the plant 

 changing its behavior towards gravitation. 

 The stem changes from negative geotropism 

 to diageotropism. 



Fiirtlier Observations on the Nature of 

 Color in Flants: Dr. Henry Kr^iimer, 

 Philadelphia College of Pharmacy. 



1. According to the author's studies, 

 plant color substances may be divided into 

 two classes: {a) Organized color principles, 

 which are characterized by being an or- 

 ganic part of the plastid body, these being 

 insoluble in water or dilute alcohol, but 

 soluble in xylol and similar solvents; and 

 {})) unorganized color principles, which 

 are not a fundamental or organic part of 

 the plastid, these occurring in the vacuoles 

 of the cells of the higher plants as well as 

 fungi, and in the vacuolules of the plastids 

 of the broM'n and red seaweeds, being fur- 

 ther distinguished by being soluble in water 

 and dilute alcohol and insoluble in xylol 

 and similar solvents. 



2. In the photo.«ynthe-is ( f the chloro- 

 plast the unorganized color substances may 

 be produced in comparatively large 

 amounts, as in {a) early spring foliage; 

 (Z>) autumnal foliage; (c) the foliage of 

 alpine plants; {d) the brown and red 

 marine alga^ ; (c ) the foliage of certain 

 species or varieties of rose, beech, nastur- 

 tium, etc. 



3. The original color of the unorganized 

 color principle is neither blue as stated by 

 Wiesner, nor red as given by Berzelius; 

 but these colors, namely, blue and red, and 

 their various shades and tints are depend- 

 ent upon substances dissolved in the cell 

 sap and which are associated with the color 



