BOTANY. 215 



4, every iiiiitli row was diiu- at intervals of 10 da_ys. The total yield 

 of tubers and yield of marketable size is yiven, showing- that a consid- 

 erable portion of the yield of marketable tul^ers was foi-med after Sep- 

 tember 1. 'rii(> unsi)ray('d vines in this experiment were nearly all 

 dead before Auoust 20. The results of this experiment lead the 

 authors to repeat the former statement that "the potato crop of Ver- 

 mont sutlers far more each year than is g-enerally realized from the 

 premature death of the vines.'' 



Development of the buds of the wild plum, L. K. Waldron 

 {Nortli Dakota Sta,. Rpt. 1899, pp. Sl-39^ figs. 6). — Investigations 

 have been made on the time and manner of differentiation of leaf and 

 flower buds, and the influence affecting the formation of flower buds; 

 also a study of the reserve materials of the plant. 



The present report is in the nature of a preliminary one, some phases 

 of the work being still under investigation. Amon^ some of the more 

 important deductions drawn from the inyestigations, the author states 

 that the stamens, pistils, and bud scales must lie considered as modi- 

 fled portions of the tissues of the shoot axis and not as modifled foliage 

 leaves. In the plant investigated th(> luimber of flowers starting in a 

 bud is -i. which may often lie lessened l)y some ])eing killed. Lignin 

 is formed early in the life of the bud, and by September the lignitied 

 portion is sharply differentiated froiu the cellulose portion. The 

 organic parts of the flower are formed liefore winter, the ovule in the 

 spring. The most important tiuie of difl'erentiation of leaf and flower 

 buds appeal's to be from the middle of July to the middle of August, 

 although there is some evidence to show that it may take place later. 



The effect of centrifugal force upon the cell, D. M. Mottier 

 {Ann. Bot., IS {1899), No. hi, pp. 32f>-o61, pi. i).— The author has 

 undertaken to determine what parts of the living su])stance and its 

 inclusions could be displaced within the cell by means of centrifugal 

 force several hundred times greater than that of gravity, acting for a 

 definite but usually short period of time, and to see what efl'ect such 

 displacement might have upon the individual cell. 



Various alga?, leaves of mosses, trichomes of a numlier of plants, 

 staminal hairs from Tradescantia, leaves of a number of plants, and 

 .seedlings of maize, beans, castor lieans, and horse beans were used in 

 the experiments. The centrifugal force was generated by the use of 

 an ordinary milk separator driven by a gas motor. After subjecting 

 the plants to this force for a number of hours it was found in the case 

 of the algas and mosses that the chlorophyll in the cells was all forced 

 toward the distal end. This was also true of the contents of the cells of 

 most of the other plants experimented with. After standing a time the 

 normal condition of the distribution of the cell contents was resumed, 

 at flrst rapidly l)ut later very slowly. 



The experiments with the seedlings of the plants mentioned were 



