MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 1 9 



Another attempt to establish a correlation among the members of 

 the shoot and root systems was made by C. Kraus'"'"' in 1878. He 

 believed he had demonstrated that the smallness of etiolated leaves 

 was caused directly by the excessive elongation of the internodes and 

 the increased length of the shoot was accompanied by a similar 

 decrease in the root-sysem. These measurements were thought to 

 be correspondent to the degree of turgidity exhibited by the organs 

 concerned. 



Vines" made two series of experiments to ascertain the direct 

 relation of light to growth in 1878, at the laboratories in Wiirzburg. 

 Partial spectra and atmospheres lacking carbon dioxide were used 

 in some of the tests. From direct measurements of the rate of elon- 

 gation of sporophores of Phycomyces in darkness and light, and in 

 various portions of the spectrum he concluded that light retards 

 growth by the direct action of the blue-violet rays, and this effect 

 was supposed to be due to a decrease in the mobility of the micellae 

 of the peripheral layers of protoplasm. These conclusions, as well 

 as the more important generalizations made by Sachs, are given by 

 Vines in his text-books of plant physiology and botany and do not 

 need further description here. 



Godlewsky "■' took up the subject for the second time in 1879 and 

 his principal results may be stated as follows : The organic material 

 in an etiolated seedling, and in one grown in atmosphere lacking 

 carbon dioxide is not greater than the amount present in the seed, 

 and is approximately equal in the two instances. The altered 

 form of the stem and cotyledon is not due to altered assimilation. 

 The total amount of dry material in cotyledons of etiolated seed- 

 lings of Rafhantis is less than in green ones. Roots of etiolated 

 plants may be slightly less developed than in the normal, yet no 

 regular correlation appears between the root and shoot in this con- 

 nection. 



s^Kraus, C. Ueber einige Beziehungen des Lichtes zur Form und Stoffbildung der 

 Pflanzen. Flora, 61 : 145. 1S7S. 



"Vines, S. H. The Influence of Light upon the Growth of Leaves. Arb. a. d. 

 Bot. Inst. i. Wiirzburg, 2 : 114. 1878. 



Vines, S. H. The Influence of Light upon the Growth of Unicellular Organs. 

 Arb. a. d. Bot. Inst. i. Wiirzburg, 2 : 133. 1878. 



Vines, S. H. Physiology of Plants. 1886, and Student's Text-book of Botany. 

 1896. 



65 Godlewsky, E. Zur Kenntniss der Ursachen der Formanderung etiolirter Pflan- 

 zen. Bot. Zeitung, 37 : 81,97, 113, 137. 1S79. 



