304 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



in the cotyledons. The amount of starch was greatest in etiolated 

 leaves, normal hypocotyls, etiolated first internodes, normal inter- 

 nodes above etiolated roots, and normal cotyledons. Cellulose 

 was present in smaller proportions in etiolated leaves, hypocotyls 

 and lower internodes, and in greater proportions in etiolated 

 upper internodes, roots and cotyledons. These determinations of 

 cellulose are undoubtedly faulty, especially in the stems. Protein 

 was present in greater proportion in etiolated leaves, hypocotyls, 

 stems and roots, and in smaller proportion in cotyledons than 

 in the normal. These results do not agree with those obtained later 

 by Palladin (p. 23). The amount of ash in a given weight of mate- 

 rial was greatest in etiolated leaves, hypocotyls, internodes and roots, 

 and less in cotyledons than in the normal, which is in general agree- 

 ment with the results obtained in my own analyses. Rzentkowsky's^"* 

 examination of seedlings of Phaseolus muItffJorus led him to con- 

 clude that etiolated plants do not take up mineral substances from 

 the substratum a conclusion which is undoubtedly wrong, as demon- 

 strated bv Andre and myself. 



THE RATE AND MODE OF GROWTH AS AFFECTED 

 BY LIGHT AND DARKNESS.-"^ 



The rate of growth of any organism varies in such manner that 

 a more or less irregular acceleration is shown during the earlier stages 

 of development until a maximum of increase is reached, when a simi- 

 lar diminution brings the action to zero. Minor maxima are also 

 shown before or after the major in some instances. In addition to 

 this major movement which traces the curve of the grand period of 

 growth of the organism, minor deviations occur, which may be due 

 to alterations in temperature, food-suppl}', moisture and other causes. 

 Running through the major and minor alterations as above there are 

 seen to be more or less regularly recurring accelerations and dimi- 

 nutions of the rate, which ha\'e been shown to be due to a rhythm 



^°^ Rzentkowsky, T. Unteisuchung ueber Entwickelung des etiolirten Phaseolus 

 multijlorus. Mitth. d. Unlversitat z. Warschau. 1875. Abstract by Batalin in Bot. 

 Jahresber. 4 : 745. 1S75. 



^'''Presented before the Botanical Society of America, at Washington, I). C, Jan. 

 1, 1903. 



