3i8 



The Ohio Naturalist. 



[Vol. XIV, No. 7, 



and other starch trees examined. In the sections illustrated, 

 it is apparent that more starch is stored in the root tissue than 

 in the stem; but the relative volume of stem and root would have 

 to be known, before it would be possible to detemiine whether 

 a greater absolute volume of starch is stored below than above 

 ground. 



It is now the purpose to record, as far as possible, in what man- 

 ner the starch thus stored is used. In this connection, there are 

 at least five considerations: as, (1) the amount used when a tree 

 is tapped, (2) the amount used when the flowers are fonned, (3) 

 when the leaves are formed, (4) when wood is formed, (5) when a 

 heavy "seed year" occurs. Of these, seed production is to be 

 given special attention, since the maple, in common with most of 

 the Ohio forest trees, is known to have regularly recurring periods 

 of heavy seed production. The particular tree chosen is a car- 

 pellate tree, and, from its numerous flower buds, it is predicted 

 that the current year is to be a "seed year." (1) and (2) are now 

 complete and it seems best to give results in this paper, rather than 

 delay until all is finished. 



To test the sugar production, the seven tree species tabulated 

 below were tapped in a manner somewhat similar to the way the 

 birch is tapped in Russia. Borings 1}4 inches deep were made by 

 a drill I inch in diameter, and a straw, cut from a thrifty stem 

 of wheat, of a diameter to fit the hole snugly, was inserted far 

 enoiigh merely to penetrate the bark. One-pint Mason jars with 

 water-proof card board caps, perforated to receive the straw, were 

 suspended to collect the sap. 500 to 1000 grams of sap were col- 

 lected from each tree, evaporated in a large porcelain evaporating 

 dish in the laboratory, and the following percentages of sugar 

 determined : 



Species 



1. Acer nigrum Mx 



2. Acer saccharum Marsh.. . 



3. Acer platanoides L 



4. Acer saccharinum L 



5. Acer negundo L 



6. Bctula allsa L 



7. Betula papyrifera Marsh. 



Date 



April 6 

 April 9 

 April 9 

 April 7 

 April 6 

 Mar. 31 

 April 4 



Per cent 

 sugar in sap 



7% 

 4% 

 2/0 

 1% 

 7% 

 2% 



1-1% 



Grams sap 

 per hour 



250 g 

 62 g 

 3o g 



125 g 



500 g 

 62 g 



100 g 



Grams sugar 

 per hour 



6 



7 g 



1.5 g 



.8g 



2.6 g 



8.5 g 



■7 g 



1.1 K 



The birches produced a clear, amber colored, wax-like .sugar, 

 which does not granulate. The ]jer cent is less than in any of the 

 maples. In Ru.ssia, the birch is quite generally tapped. Some- 

 times this sa]3 is fermented to make birch wine. Of the maples, 

 Acernigrum Mx., the 1)lack maple, had the greatest concentra- 

 tion of sugar in the sap, which confinns the statement in Bull. 

 516, U. S. Dept. Ag., p. 8. But the box elder, Acer negundo, a 



