48 SEVENTH REPORT OF THE FOREST, FISH AND GAME COMMISSION. 



edly, an early frost may precipitate a change by prematurely hastening the decay 

 or death' of the leaf ; but the resultant color will be inferior, changing soon to the 

 dull brown which characterizes sear, dead foliage. Moreover, when the fall months 

 are cool and dry the leaves are persistent, and afford a longer display of autumnal 

 tints. 



Nor is frost necessary to the falling of the leaves.* Throughout our Northern 

 States much of the foliage of the trees falls before any frost occurs, while in the 

 South the deciduous trees denude their branches without its aid. Frost can kill, 

 but it cannot ripen vegetation. It has been noted also by close observers that 

 while an early frost will check the development of bright leaf colors, a hot, sunny 

 day, about the first of October, will have the same result and loosen the leaves so 

 that they will fall in showers when stirred by the first gentle breeze. 



In preparing the colored illustrations of autumn leaves, shown in the accompany- 

 ing plates, great care was taken to place the specimens as soon as possible in the 

 hands of the artist on whom devolved the task of reproducing the exact tints. This 

 was found to be especially necessary with the yellow leaves, as this class when taken 

 from the tree faded quickly to some extent. With the reds there was not so much 

 need of haste, these colors being more persistent. In order to avoid delay in this 

 respect as far as possible, the specimens were collected mostly in Bronx Park and 

 Northern New Jersey, although excursions for the same purpose were made to the 

 Berkshires and Catskills. 



No attempt was made at scientific research ; it was sought rather to offer in 

 connection with the text some illustrations showing the typical color assumed in 

 autumn by me leaves of our most common trees, illustrations which might furnish a 

 convenient reference for naturalists if ever needed. 



The collection was made by Mr. Abraham Knechtel, F. E., a forester in the 

 employ of this Department, whose scientific attainment and love of nature-study 

 rendered him well qualified for the work. Ample acknowledgment is also due to 

 Mr. William E. Bruchhauser, of New York City, the artist whose skill and enthusi- 

 astic co-operation made the accurate reproduction of colors possible. 



♦Kerner and Oliver. Natural History of Plants. Vol. II, p. 355. 



