Maple family 



Much of ihe splendor of our radiant forest; in early 

 autumn is due to tlie bnllianl coloring- of the Sugar Maple. 

 It glows in red which deepens nito crimson, it flames in yel- 

 low that darkens into orange. The^e wonderful leaves will 

 show colors as pure as anv on the finest porcelain ; a dark 

 green leaf will show a single spot ot crimson, a dark retl 

 bears a single lobe of rose pink. The next will have a patch- 

 work of vellow and purple and scarlet, like a palette set for a 

 sunset picture. Si_mietimes a single branch will turn bright 

 scaidet wliile all the rest of the tree remains green. Indi- 

 vidual trees varv in time and manner of change, ami to some 

 degree these peculiarities are fixed ; for example, certain 

 trees alwavs turn veliow, others al\va\'s turn red, while there 

 are others that varv with changing conditions. 



There seems to be a very general popular impression that 

 the colors of the leaves in autumn are dependent upon the 

 frosts. Careful oliservation does not sustain this view. It 

 is true that the brilliancv of the autumnal coloring varies; 

 but the changes are now referred rather to the character of 

 the preceding summer than to the frosts of autumn. If the 

 summer has been rainy, keeping the leaves fuli of sap and 

 the cuticle thin and disteiuled, the autumn tints are l)riniant ; 

 but if the summer has been drv the tints are ilnll. 



Two great problems are conneclctl with the fall of the 

 leaves of deciduous trees. ()ne, why do thev take on such 

 gorgeous colrirs ; and the other, how is it the\' fall leaving 

 no open houihIs behind ? \\'hat are the morphological and 

 physiological changes which produce these results ? The 

 following is jierhaiis as clear a statement of the present 

 opinion ot biologists as can be given in popular form : 



Tlie c.l^tinL; of tlie iMf is not ."i sudden and quid; response to anv single 

 ch.-inse in enviionim-ninl condili.ms, but is brought about with a complex int. r- 

 play of pr<.>ce-s<-s begun tiays or perhaps weeks before an\' external changes 

 are to be seen. Tlie leal" is rich in two classes of substances, one of which is of 

 no further Ijenefit to it, and another whieh it has cetnstrtieted at great expense 

 of energy, and which is in a form of the highest possible uselulness to the plant. 

 To this class belong the compounds in the protoplasm, the green color bodies, 

 and whatever surplus food may not have been previously conveyed away. The 



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