44 



HAERINGTON ON THE SAP OF ASH-LEAVED MAPLE. 



Table V. — Acer saccharinum. 



The most complete series of determinations which I have seen, however, is that 

 published by Dr. Wiley in 18'79. ' Specimens of sap were taken from twelve different 

 sugar maples {A. saccharinum) selected so as to represent in size, shape, age, etc., the average 

 growth of a grove situated at Lafayette, Indiana. The determinations were made (with 

 polariscope) on March 21st and 25th, and the average for the twelve trees vras 2.93 per 

 cent, of sugar on the former date, and 2.44 on the latter. The mean of these percentages 

 (2.685) is only 0.31 per cent, higher than the average for the two negundos. In the case 

 of three freshly tapped trees, Wiley obtained respectively 3'93, 3.*75 and 2.42 per cent. 



It is well known that the sap of the red maple (A. rubrum) is frequently made use of 

 for the production of sugar, although the average yield is admitted to be much lower 

 than in the case of the true sugar maple. While the experiments with the negundos were 

 being carried out, a large red maple near by was tapped and an examination made of the 

 sap on five successive days. The results are given in the following table : — 



Table VI. — Acer rvbr 



urn. 



' Proc. Amer. Assoc, for Adv. of Sc. 1879, xxviii. 234. 



