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Department of Botany, 



Wellesley College, Wellesley, Mass, 



£:x:plaiiatioii of text Hsrnres antl of plates 9-li 



Figures v^-y represent the curves of growth of the buds in length and in diam- 

 eter. Figure A" is the temperature curve. The continuous line indicates growth in 

 length. The dotted line indicates growth in diameter. The dot and dash line shows 

 the mean temperature. The numerals on the axis at the left of curves ^-y represent 

 the growth of the bud in millimeters. The numerals at the right of curve A" indicate 

 the mean temperatures, Fahrenheit, The bottom line represents the time during 

 which measurements were made, the 25th of November, December, and January, the 

 loth and 25 th of February, March, April, and May. As a rule, for each species, the 

 measuiements of ten buds are averaged for each curve. The curves, end at the time 



of unfolding of the bud. 



AH figures in plates 9-11 were drawn with the aid of the Abb6 camera lucida. 

 A Zeiss microscope was used. All figures represent longitudinal sections. Figures I 

 and 8 are magnified to times ; all others are magnified 25 times. The abbrevia- 

 tions used in the explanation of plates are as follows t 



Axis of incipient shoot, a,; axillary bud, ax.b.\ base of petiole, *./.; leaf, A; leaf 

 fundament, /./.; petiole,/.; scaly covering, s.c; scale fundament, j./; stipule, sL\ 

 terminal bud, tj.\ vegetative point, v./,; vascular tissue, vj. 



y 

 J 



