75. 



of the scale was found pressing closely against the surface 

 of the leaf, other sections, on the contrary, seemed to show 

 that the scale stood up a"bove the surfao .-^ -".hat there 

 was a space "between the surface of the leaf and the wing 

 of the scale, A similar beha.vior of the scales was also 

 observed in sections of the expanded leaf, It is therefore 

 difficult to grascrihe any definite function to the scales,* 

 There are some indications that they aid in the absorption 

 of water for the thick walled cells of the wing were seen 

 to absorb water rapidly, Whether the v/ater aborbed by the. 

 thick cell walls of the wing \jQ$k later carried over by 

 capillarity to the living stalk eells euid from there to the 

 interior of the leaf the writer is unable to say v/ith any 

 degree of def initeness.It is also possible that they help 

 to protect the plant against drought, Their primary function 

 seems to be, however, that of holding a film of water on the 

 under surface of the leaf long enough to allow sufficient 

 water to be imbibed by the cell walls and in that way to 

 help restore the leaf to the expanded form,This is particularly 

 suggestive when one considers the short time it t9,kes a 

 dry and curled leaf ; to expand after a rain, Long before the 

 roots v/ithin the bark are able to take up and supply to 

 the leaves the water absorbed by the bark during a rain, 

 the 3«r.Ies by holding a film of v/ater over the entire surface 

 of the leaf allow the surface cells to absorb water and to begin 

 to enlarge 3010. thus to begin the uncurling of the leaf," 



