16 Wisconsin Academy of Sciences, Arts, and Letters. 

 t 



very large quantities of starch, which gradually diminished up- 

 ward to the branches where it increased again but none was pres- 

 ent in the season 's shoots. In the wood of the stump the starch 

 was also abundant especially in the rays. It decreased upward 

 to the branches and in the season's shoots only a little was pres- 

 ent near the pith. The fat content of the bark increased from 

 the ground upward but beyond the four-year-old branches there 

 was but little fat present. In general less fat than starch was 

 present in the wood of the stem but it gradually increased from 

 the ground up to the branches. 



A marked starch increase in the wood since September was evi- 

 dent while the fat content had not been correspondingly reduced, 

 in fact it was considerable in the branch-bearing part of the 

 trunk. The distribution and relative amounts of reserve food 

 was very similar to that found on the preceding February. It 

 is therefore thought evident that starch does not diminish early 

 in the dormant season and that it is retained as starch through- 

 out winter. 



The bark of the roots had an increasing amount of starch 

 toward the stump until a maximum was reached in roots 2 to 3 

 cm. in diameter after which it diminished. The wood contained 

 considerable starch in as many as thirty of the outer rings near 

 the stump and then the number of starch bearing rings decreased 

 peripherally as it did in the stem from the ground upward. In 

 an excentric root with a radius of 44 mm. on one side and of 7 

 mm. on the other twenty rings contained starch on the thicker 

 side and ten on the other. The thicker side had 70 rings and 

 the opposite side 20 showing that during 50 growing seasons no 

 radial growth had occurred on the thinner side. The roots con- 

 tained considerable fat which diminished toward the stump. 



In this case as well as in the tree cut in February the young- 

 est 'phloem and the included portions of the phloem rays besides 

 the outer cortex contained very little starch while that portion of 

 the bark between them contained much starch. Fabricius thinks 

 that the characteristic 'browning of the inner phloem so com- 

 monly noted in late winter and spring, which has been attributed 

 to the action of atmospheric electricity by Tebeuf , 28 ;probably has 

 a relation to this distribution of reserve food in the bark. 



"Tubeuf, K. von. Beobachtung uber elektrische Erscheinungen im 

 Walde. 



Naturw. Zeit. Land-u. Forstw. 3:493-507. 1905. 



