18 Wisconsin Academy of Sciences, Arts, and Letters. 
June and included both hard and soft wood trees. It was found 
that all starch disappeared in winter from Populus deltoides, 
Salix alba and Juniper us virginiana, while Quercus rubra , Ulmus 
americana, Acer saccharum and Juglans nigra retained consid¬ 
erable starch in the wood through the winter. Tilia americana 
underwent a starch reduction but retained some in the phloem, 
medullary rays, and xylem, while Carya glabra lost its starch 
in small stems but retained about a fourth of it in larger stems. 
None of these trees except Carya showed a reduction of starch 
in the roots during winter. Large amounts of sugar were found 
present only in spring as the buds were unfolding. The trees 
tested had a maximum fat content in late fall and a minimum in 
spring. These tests seem to show that broad-leaved hard wood 
trees cannot be called starch trees nor those with soft wood fat 
trees, as had been done by Fischer. 
Niklewski 31 concluded from his study that the starch conver¬ 
sion in soft wood trees like Tilia, Betula, etc. is practically com¬ 
plete on the approach of winter, while in hardwood trees like' 
Prunus and Syringa it is only partial. It was found that fats 
are more abundant in winter and also that a rise in temperature 
increased the amount. 
According to Wotczal 32 starch transformation begins in spring 
in the distal parts of shoots and roots and proceeds towards the 
older portions of the tree, although it starts later in roots than 
in the shoots. But normally these two waves of starch trans¬ 
formation starting in the roots and shoots do not encounter one 
another, and in this way a starch residue remains in the older 
wood and in the region of the root-crown. The deposition of 
starch then occurs in the reverse manner throughout the tree, 
i. e. it begins in the oldest parts and around the root-crown and 
proceeds wave-like toward the distal ends of the shoots and roots. 
The work by Fabricius reviewed above shows that remarkable 
and apparently wave-like progressive changes occur in the state 
and distribution of reserve foods in trees and that maxima and 
minima of the different types occur in certain parts at rather 
definite periods of the seasonal history. The above cited experi- 
81 Niklewski, B. Untersuchungen liber die Umwandlung einiger 
stickstoffreier Reservestoffe wahrend der Winterperiode der Baume. 
Beihefte Bot. Centralbl. 19 Abt. 1:68-117. 1906. 
32 Wotczal, E. Die Starkeablagerung in den Holzgewachsen. Bot. 
Centralbl. 41:99-100. 1890. 
