36 PHENOMENA OF PLANT-LIFE. 



such beeches in open land have an unusual amount of sap- 

 wood, and are hence called white beeches. 



A red maple, on the College farm, which was girdled in 

 April, 1873, by cutting a channel in the sap-wood two inches 

 wide and one inch deep, bled most profusely, but grew as 

 usual through the season. No wood, however, was formed 

 below the girdle, and the bark died and separated from the 

 wood. The roots, nevertheless, remained alive, and the tree 

 has borne its usual amount of foliage during the summer of 

 1874, and formed its buds for next year, and produced a new 

 layer of wood above the girdle. Specimens have been col- 

 lected for chemical and microscopic analyses of the roots and 

 of the wood and bark above and below the girdle, in the hope 

 that some light may be thrown upon the subject of sap circu- 

 lation and the functions of the bark, whenever this work can 

 be done. 



On the third of June last, branches of the apple, pear, 

 peach, crab-apple and grape were girdled by removing a 

 ring of bark one inch long. They grew well and bore an 

 abundance of fine fruit, as was expected. 



On the fourth of June, small trees of red maple, elm, 

 aspen; willow, linden, chestnut, white pine, black birch, but- 

 ternut, and a large wild grape vine, were girdled by remov- 

 ing a ring of bark two inches in length. 



On the twelfth of June, trees of ash, bass, beech, black 

 birch, yellow birch, white birch, alder, black oak, chestnut, 

 sugar maple, hornbeam and ironwood were girdled in like 

 manner; and on the twenty-third of June, specimens of white 

 oak, red oak, black birch, yellow birch, white birch, red 

 maple, sugar maple, ash, bass, aspen, witch-hazel, white 

 pine, cornel, chestnut, hickory, beech, ironwood, hornbeam, 

 apple and choke-cherry. July twenty-first, we girdled speci- 

 mens of wild grape, cornel, red maple, chestnut, black birch, 

 white birch, white pine, bitternut, white oak and black oak. 



On the twenty-eighth of August, the bark of the following 

 species was found to adhere to the wood, viz. : red maple, 

 yellow birch, wild thorn, hornbeam, beech, witch-hazel, bird- 

 cherry, white oak, red oak, elder and elm ; while the bark of 

 the following species was readily separated from the wood, 

 viz. : hemlock, white pine, alder, shadbush, white birch, 



