35 



hastens the breaking up of the chlorophyll, but individual 

 trees often show bright colors long before the first frost,'" etc. 



He, it appears, is not certain that frost has any effect 

 upon color, and seemingly can assign no reason for the 

 change of color before frost. Mr, Bergen's ideas and lan- 

 guage are very similar to those of Doct. George L. Goodale, 

 a much earlier writer, in his PJiyHological Botany, who 

 says: "That frost is not essential to the production of the 

 leaf-colors of autumn is plain from the widely known fact, 

 that many leaves undergo precisely these changes of color 

 lo7ig bejore any frosts appear. It is generally believed how- 

 ever that f-eezing may somewhat hasten the process of chloro- 

 phyll disintegration which underlies all the changes." 



Geo. B. Emerson in Report on the Trees and Shrubs of 

 Massachusetts, writes as follows regarding the Scarlet Oak, 

 p. 166, vol. 1 : "The leaves after they have undergone this 

 change of color vjhich has no dependence on the action of frost, 

 remain long upon the tree," etc. 



The Scarlet Oak here, in the vicinity of New Bedford, 

 was scqj'cely changed at all before the frosts of Oct. 16-20. 

 A letter from the Arnold Arboretum, dated Oct. 23, 1900, 

 states that: "The foliage of the Scarlet Oaks is just be- 

 ginning to turn here." Advices from other points in New 

 England were of a similar tenor. 



Again quoting Emerson, p. 552, vol. 2: "The observa- 

 tions for a single year of the varying colors of the red maple 

 Avould be sufficient to disprove the common theory that the 

 colors of the leaves in autumn are dependent on the frosts. 

 It is not an uncommon thing to see a single tree in a forest 

 of maples turning to a crimson or scarlet in July or August 

 while all the other trees remain green. A single brilliantly 

 colored branch shows itself on a verdant tree, or a few 

 scattered leaves exhibit the tints of October while all the 

 rest of the tree and wood have the soft greens of June," 

 etc. "The frost has very little to do with the autumn 

 colors." But, the "single tree," "single brilliantly colored 



