PHENOMENA OF PLANT-LIFE. 47 



thirtieth, bled six drops per minute. The buttonwood flowed 

 forty drops per minute, March twenty-fifth, and one hundred 

 on a very cold day, the eighth of April. The total amount, 

 however, was very small. The apple bled twenty-eight drops 

 per minute, May thirteenth, and the beech, on the tenth of 

 May, flowed ten drops per minute, both yielding most sap in 

 decidedly warm weather, the mean temperature for the last 

 date being above 70 F. The latex of the mulberry exuded 

 from the bark, on the ninth of April, as a transparent fluid 

 which soon became milky, and the white and yellow pines 

 flowed a small quantity of turpentine, apparently from both 

 bark and wood. 



A large red maple, which was thoroughly girdled in 1873, 

 and whose bark had died and peeled off below the girdled place, 

 was tapped above and also below it. The result was that it 

 bled freely from both holes on many occasions. The flow, on 

 the eighth of April, was fifty drops per minute from the upper 

 one, and one drop from the lower one, while on the eleventh 

 of the same month, it was three drops from the upper and 

 fourteen drops from the lower one. 



After the usual run of sap for the season has ceased, some 

 species will bleed from the stump, if cut down, just like many 

 herbaceous plants. Thus, Mr. Win. F. Flint reports that 

 large trees of the black, yellow, and paper birch, when felled 

 on the thirtieth of June last, did not bleed immediately, as in 

 April, but after an hour or two began to exude sap freely. 



On August twenty-eighth, twenty-four species of young 

 trees were cut down, about one foot from the ground, to see 

 whether they would bleed. None did so immediately, but 

 fifteen hours afterward the black birch ran a few drops, and 

 the following were moist on the top of the- stump, viz. : alder, 

 yellow birch, red maple, cornel, ironwood, apple, elder, elm, 

 and white pine. August thirty-first, the black birch bled a 

 little, and the yellow birch, thorn, apple, glaucous willow, elm, 

 and white pine were moist. The rest, including hemlock, 

 shad-bush, white birch, chestnut, hornbeam, beech, ash, witch- 

 hazel, bird cherry, white oak, red oak, and aspen, were per- 

 fectly dry, though all were sheltered from the sun. 



These results seem to include most of the important attain- 

 able facts in regard to the flow of sap as exhibited by our com- 



