54 



Scientific Proceedings, Royal Dublin Society. 



A particularly favourable opportunity for studying the variation in the 

 composition of the sap, both with respect to the height above ground and to 

 the season, was afforded by three tall stems from a large old stump of Acer 

 macrophyllum growing in the Botauic Gardens of Trinity College, Dublin. 

 Two of these, felled in October and February, were as similar as two trees 

 could possibly be, and sap was obtained from them at intervals up to 10 metres. 

 The third, felled in April, was slightly smaller, but afforded material for 

 examination up to 9'5 metres. The results are given in Tables II-IV. 



Table II. 

 Acer macroyphyllum, October 13th. 



Table III. 

 Acer macrophyllum, February 25th. 



