studies on Growth and Cell Division in the 

 Root of Vicia Faba. 



(WITH PLATE XVIII.) 



Bv Blanche Gardner, B. S. 



These studies were originally undertaken to determine the 

 growth of the root under varied environmental conditions ; 

 but during the progress of the work, several additional inter- 

 esting lines of study have suggested themselves. So the work 

 has been extended, and can now be grouped under the fol- 

 lowing heads : 



A. Daily Periodicity of Growth in Roots. 



B. Relative Growth of Roots in Different Chemical Solutions. 



C. Cell Division. 



The studies on the root of Vicia Faba were suggested to 

 me by Professor J. M. Macfarlane and I wish here to 

 acknowledge my indebtedness to him for suggestions and 

 criticisms of my work. 



A. Daily Periodicity of Growth in Roots. 



To determine the rate of growth in roots, during day and 

 night, a series of experiments were performed in which seed- 

 lings of the broad bean ( J'^icia Faba) and of the pea i^Pistan 

 sativuvi) were used. The seeds were germinated in moist 

 sawdust. When the roots reached a length of about one to 

 one and a half inches, they were used for experimentation. 

 Wooden boxes, with one side of glass, were loosely packed 

 with the moist sawdust, and in these the seedlings were 

 placed with the root in a horizontal position against the sur- 

 face of the glass. Marks could therefore easily and accurately 

 be made on the glass at different hours of the day. The 

 roots were thus arranged, and observations were usually made 

 ■from lo A. M. to 4 p. m. and at 9 a. ji. the following day. In 



(J50) 



