1918] SINNOTT—FOOD RESERVE 165 
Two other general relations between anatomy and the character 
of the food reserve were noted. Species with diffuse-pored woods 
are usually either fat trees or have an abundance of fat; those with 
ring porous wood are almost always starch trees. Narrow-rayed 
species may belong to either category, but broad-rayed types are 
prevailingly starch trees. 
By no means all the species studied could be classed definitely 
as starch trees or fat trees. The oaks, ashes, and hickories belong 
clearly to the former category, and the pines and lindens to the 
latter; but very many species are intermediate in character, 
possessing both fat and starch in the wood of the stem. In many 
instances, also, storage material was noted which was neither starch 
nor fat but seemed somewhat intermediate in character between the 
two. The outlines of the original starch grains could sometimes 
roughly be made out, but the starch content of the cell was appar- 
ently coalescing into an irregular brownish mass. This was insol- 
uble in ether and stained neither with iodine nor Sudan III. Its 
bulky, opaque character indicated that it was actually storage 
material and not merely the cytoplasm of the cell. It was evident 
chiefly during the winter, occurring frequently in the cortex as well 
as in the wood, in cells which had been filled with starch. SurRoz 
(6) called attention to the existence of such material, but apparently 
it has not been noted by others. If it is indeed a stage in the 
transition from starch to fat, its composition might perhaps throw 
light on the difficult problem of the chemistry of fat production in 
the cell. 
Table I presents a rough outline of the character of the food 
reserve in the pith and wood of the stem (twigs and young 
branches) of the more common trees and shrubs during the mid- 
winter months, dividing them into those where fat predomi- 
nates, those which possess considerable amounts of both starch 
and fat, and those in which starch predominates. This classifica- 
tion should not be regarded as rigid, since a considerable varia- 
tion has been noted in some of the species and genera, but it 
represents the average condition observed for each. The character 
of the reserve in phloem and cortex of course is not included in 
this table. 
