234 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



lutely exclusive of light. The examination of etiolating material in 

 a dark chamber by opening a door that would admit daylight would 

 of course vitiate the experiments by reason of the light stimulation 

 ensuing in consequence of this exposure. Sachs says: "From the 

 large seed of a bean or horse chestnut, on the contrary, there may 

 be produced in the dark a plant of considerable size with copiously 

 branched roots and several, though small and yellow, leaves.""''^ The 

 specimens of horse chestnut grown in my own experiments did not 

 develop a root system in darkness equal to that in light. The sparse- 

 ness of the root-S3^stem of this plant when etiolated is shown in Fig. 

 150. Detmer'"" noted the lack of full development of the roots of etio- 

 lated plants and ascribed it to the lack of the synthetic function of 

 the leaves upon which the root-system was supposed to be directly 

 dependent. But little doubt remains, however, that an etiolated shoot 

 with lenticellar openings, stomata and other transpiratory devices, 

 would necessaril}^ be accompanied by a more fully developed absorb- 

 ing system than one in which but little water was taken up or used 

 by the shoot. Vogel relates that tiie roots of plants grown in dark- 

 ness are more developed than those which have been cultivated in 

 light, a statement put forward by him as a result of measurements of 

 the aerial and submerged roots of Bombax and Hiwa crepitans^ 

 which does not afford any real proof of the statement in question, 

 however. Lasareff found that the branches of adventitious roots of 

 a large number of seedings were both fewer and shorter than in nor- 

 mal specimens, but he mistakenly supported the assertion credited to 

 Famintzin by which such correlation was supposed to exist between 

 the roots and shoots, that the longer the shoot of an etiolated plant, 

 the shorter would be the root-system.'"^ 



Strehl '"■ found that the rate of growth of roots of etiolated plants 

 was generally greater than that of plants subject to the alternations of 

 day and night for the brief period in which measurements were 

 made, and this may be reasonably assigned to the undoubted corre- 



"SSachs. Physiology of Plants. English Ed., p. 531. 18S7. 



'""Detmer, W. Die Formbildung etiolirter Pflanzen. Vergleichende Physiologie 

 des Keimungsprocesses der Samen. Pp. 464-47S. 18S0. 



"' Vogel, A. Beitrage zur Kenntniss des Verhiiltnisses zwischen Licht und Vege- 

 tation. Flora, 39 : 385. 1856. 



Lasareff, N. Ueber die Wirkung des Etiolirens auf die Form der Stengel. Ab- 

 stract by Batalin. Bot. Jahresber. 2: 775. 1874. 



"^Strehl, R. Untersuchung ueber das Liingenwachstum der Wurzel und des 

 hypokotylen died. Leipzig, 1S74. 



