RELATION OF LEAF STRUCTURE TO PHYSICAL FACTORS 63 



temperature 48-72 : diphotophyll 175/4; epidermis 20 /i; chlor- 

 enchym (i35/u.) 2 loose rows of subglobose palisade cells 25/4; 

 loose oblate sponge cells. 



Meadow C. 360 ft P. 3-4 rows, iSoft S. iSoft 



Spruce C. 135 ft P. 2 rows, 50 ft S. 85 ft 



225ft 1-2 rows, I30ft (72%) 95ft (52%) 



Light 1/33; water +(2-3%); humidity +(5-10%); tempera- 

 ture (2-3). 



Prumis demissa 



HALF GRAVEL: light i ; available water 10% ; humidity 30-65% ; 

 temperature 5i-76: diphotophyll 220 /*; epidermis, upper 25/11, 

 lower 20 p; cuticle 3 /A; chlorencym (i75/*) 2 compact rows pro- 

 late palisade cells 60 /A ; loose irregular sponge cells. 



FOOTHILL THICKET: light 0.0125 ; available water 15% ; humidity 

 38-80%; temperature 53-85 : diphotophyll 150/1; cuticle, upper 

 2 n, lower thin; chlorenchym (105/1) I compact row prolate pal- 

 isade cells 40 /t, and the remains of a second row 25 /* ; lacunose 

 oblate sponge cells. 



Half gravel C. 175 ft P. 2 rows, 120 ft S. 55ft 



Thicket ... C. 105 ft P. ij rows, 65 ft S. 40 ft 



70ft irow, 55^ (46%) ISM (27%) 



Light 1/80; water +5'%; humidity +(8-15%); temperature 

 '+(2-9). 



Viburnum pauciftorum 



GRAVELLY BROOK BANK: light i; available water 8%; humidity 

 40-70% ; temperature 55-76 : diphotophyll 225 /*.; epidermis 20 /t; 

 cuticle thin, chlorenchym (185/11) 2 rows prolate and prolobate 

 palisade cells, the first close 50 /<,, the second looser 35 p. ; loose 

 irregular sponge cells. (Plate VII, fig. 50.) 



THICKET : light 0.014 ; available water 19% ; temperature 48- 

 72: diphotophyll 175/1-; epidermis 15/1; chlorenchym (145/1) i 

 loose row prolobate palisade cells 40/1; lacunose irregular sponge 

 cells. (Plate VII, fig. 5 &.) 



Brook bank C. 185 ft P. 2 rows, 85 ft S. 100 ft 



Thicket C. 145 ft P. I row, 40 ft S. 105 ft 



40ft i row, 45 ** (53%) +5/* (5%) 



Light 1/70; water -f-n%; humidity the same; temperature 



