RELATION OF LEAF STRUCTURE TO PHYSICAL FACTORS 65 



dermis 15/4, upper wavy; chlorenchym (70/4) i loose row funnel 

 palisade cells 35/4; lacunose oblate sponge cells. (Plate VII, 

 fig. 6b.) 



Half gravel C. 240/4 P. 2-3 rows, 125/4 S. 115/4 

 Thicket . . . C. 70 ft. P. i row, 35/4 S. 35 y- 



170/4 (1-2) rows, 90/4 (72%) 80/4 (70%) 



Light 1/80; water +13%; humidity +(20-30%); temperature 



Campanula petiolata 



HALF GRAVEL: light i; available water 4.5-7.5%; humidity 30- 

 65%; temperature 5i-76: diphotophyll 250/4; epidermis, upper 

 25/4, lower 20/4; cuticle 5/4; chlorenchym (205/4) 2 compact 

 irregular rows prolate palisade cells 50/4, the lower row more or 

 less indistinct; compact triangular sponge cells, lower ones more or 

 less prolate. 



THICKET: light 0.016; available water 13-18%; humidity 40- 

 70%; temperature 48-72 : diphotophyll 120/4; epidermis 20/4 

 with long cells; cuticle thin; chlorenchym (80/4) i loose row pro- 

 late palisade cells 25 p. ; close oblate sponge cells. 



Half gravel C. 205 /* P. 2 rows, 100 n S. 105 /* 



Thicket ... C. SOM P. I row, 25 ft. S. 55/4 



125/4 i row, 75 n (75%) 50/4 (47%) 



Light 1/65; water +(8.5-10.5%); humidity +(5-10%); tem- 

 perature (3-4). 



Lactuca ludoviciana 



HALF GRAVEL: light i; available water 4.5-7.5%; humidity 30- 

 65%; temperature 5i-76 : diphotophyll 175/4; epidermis, upper 

 20 /4, with cuticle 5 /4 ; lower 25-30 p., with cuticle 2 /4 ; chlorenchym 

 (130/4) i compact row prolate and prolobate palisade cells 40/4; 

 close irregular sponge cells. 



THICKET: light 0.016; humidity 40-70%; temperature 48-72 : 

 the only deviation from the type is the thinner cuticle. 



Light 1/65; water the same; humidity +(5-10%) ; temperature 



Geranium caespitosum 



HALF GRAVEL: light i; available water 4-5-7-5%; humidity 30- 

 65%; temperature 5i-76: diphotophyll 350/4; epidermis 25,*; 



