Grossenbacher—Radial Growth in Trees. 
15 
outer four rings. In the branch-bearing portion of the stem the 
outer rings again showed some starch. All the wood was rich 
in fats which usually exceeded the starch present. In the 
phloem only the youngest cells had appreciable amounts of fat. 
That is, in mid-July more fat and less starch is present in spruce 
than in June. 
Very little starch occurred in the one-year roots but it in¬ 
creased in amount toward the thicker roots so that in four-year 
roots as much starch was present as there had been in the trees 
cut before. The bark also contained much starch but very little 
fat. No fat was present in the wood of the smallest roots but it 
occurred in the larger ones and increased upward. The new 
elongation growth of the roots and the bark on the thin ones, as 
well as the young wood and phloem, were devoid of starch al¬ 
though considerable was present in the large roots. Fat oc¬ 
curred in the root wood and in occasional places in the bark. 
By the last of August an additional reduction had occurred in 
the fat content of the bark and the starch in the bark had also 
decreased from the ground upward while nearly the entire wood 
cylinder had become practically starch-free. The bark of the 
larger roots contained considerable starch but it was irregular¬ 
ly distributed. In the youngest phloem it was absent. The 
wood-rays in the larger roots and stumps had fairly large 
amounts of fat present. In general it may be said that the 
starch decreased in the aerial parts and increased underground 
since last examined in July. The transition occurring at the 
crown or stump where starch was less and fat more abundant 
than earlier in the summer. 
On September 25 the bark of the stem contained considerable 
starch but it was present in decreasing amount from the first 
branches upward to practically none in the season’s growth of 
shoots. Nearly the entire wood cylinder was devoid of starch 
excepting a small amount at its base or crown and in the inner 
living rings. Both bark and wood were rich in fats especially 
in the rays. The maximum fat content occurred about 3 m. 
above ground where starch was practically absent. All except 
the thin roots were comparatively rich in starch. In the wood 
starch increased toward the stump. The larger roots also con¬ 
tained considerable fat while the small ones had none. 
On October 28 the bark of the stem near the ground contained 
