390 BULLETIN OF THE BUSSEY INSTITUTION. 
It is to be said that in these trials no attempt was made to sep- 
arate from the starch any sugar which may have been contained 
ready formed in the woods at the moment of their examination. 
It is to be presumed that in several instances, small quantities of 
sugar as well as of starch were actually contained in the sub- 
stances examined. In the case of the ivory nut, for example, 
Reiss * found half of one per cent of sugar (‘‘ dextrose”’) soluble 
in water in a sample examined by him, and Grtissf has noticed 
that the mannan in date-stones dissolves — as it does in the act 
of germination — when exposed for a very long time to the action 
of diastase. 
It will be noticed that, in conformity with the experience of other 
observers, the analyses above given exhibit a marked tendency on the 
part of starch to accumulate in the bark of trees rather than in the wood 
proper. This fact accords with common experience in respect to the 
habits of many animals which feed upon bark in preference to wood. 
Mice and rabbits, for example, working beneath the snow in severe 
winter weather, often destroy young fruit trees by eating away the bark 
from off the wood. The beaver is known to subsist principally upon 
the bark of small limbs of the yellow birch and of certain poplars and 
willows, beside that of alders, maples, and other deciduous trees. 
According to Morgan,{ it is only in late winter that beavers eat clear 
wood § and such roots as they can reach from their burrows or find in 
the banks of streams. The American porcupine also feeds upon the 
living bark of trees stripped from their branches. 
Indeed, it was customary formerly in many countries, in times of 
dearth, notably in Sweden and Norway, to prepare bread which con- 
tained a considerable admixture of pulverized bark. So recently as 
1854, von Berg collected samples of ‘* bark-bread” in Sweden which 
nut, I am indebted to the civility of Messrs. Newell Bros. of Springfield, Mass. 
As received, the snow white turnings were contaminated with a small propor- 
tion of fragments of the dark-colored outward coating or skin of the nut, but 
pains were taken to pick out and remove these specks before subjecting 
the pure material to chemical examination: 
* Landwirthschaftliche Jahrbiicher. 18. 745. 
+ Tollens’s Kohlenhydrate. 2. 367. 
t L. H. Morgan, The American Beaver. Philadelphia. 1868, pp. 166, 183. 
§ Many years ago I was told by Jeffries Wyman that, on dissecting a 
beaver, he had found in the intestinal tract of the animal segments of birch 
twigs of considerable size, the outer bark of which was still perfectly sound, 
while the wood itself had been thoroughly reduced by the digestive juices to a 
soft, smooth pap or chyme, which could readily be scraped or squeezed out 
from the bark cylinder which held it in place. — F. H. S. 
