4°° P- Q- KEEGAN [december 



undergoes no change in winter. N. J. C. Muller was the first to 

 observe the disappearance of the rind starch in winter, and he thought 

 that it migrated into the wood. Russow, in the winter of 1880-81, 

 examined the barks of ninety-two different tree stems up to sixty years 

 old, and found starch only in ten kinds, but as compared with the 

 autumnal content it showed a great diminution ; experimenting again 

 in the colder winter of 1882, he found that in all species of tree the 

 starch had disappeared up to isolated traces, it being transformed 

 principally into fat-oil ; on the other hand, he came to the conclusion 

 that the starch had all the time remained unchanged in the wood of all 

 the species investigated. He found, moreover, that towards the end 

 of March the rind starch had been copiously formed again, i.e. long 

 before the bursting of the buds, the suppression of the carbohydrate 

 thus lasting from November till April. In 1884 Baranetzky and 

 Grebnitzky published the results of their researches. They found that 

 not only the rind starch but also the wood starch was reduced in 

 winter, and may even disappear altogether, e.g. in lime tree, fat-oil 

 stepping into its place ; on the other hand, in hard-wooded trees, while 

 the starch vanishes entirely from the rind, it remains, though somewhat 

 reduced in quantity, in the wood. In 1890 Dr. A. Fischer confirmed 

 the views of these observers, and further investigated the method and 

 course pursued in the process of the starch dissolution in fat- trees 

 during the autumn. He emphasised the opinion that the entire 

 wood-starch of the younger twigs in fat-trees is transformed on the 

 spot, i.e. the principal mass of the starch undergoes no translocation. 

 He was also disposed to conclude that the greater part of the fat in 

 the older wood of certain trees is never changed at all, whereas that 

 contained in the rind disappears almost entirely in spring and summer. 

 He further recognised eight phases of starch transformation, viz. a 

 maximum in October and in April, a minimum in December, January, 

 and February, and again in the latter half of May, a dissolution in 

 November and beginning of May, a regeneration in March, and a 

 storing up from June till October. In 1891 Monsieur Emile Mer, 

 who had studied the distribution of starch in the principal trees and 

 indigenous shrubs of France, found that in the middle of November a 

 great change had already been wrought, the starch had nearly all 

 disappeared from the cortex and liber at least in the branches as well 

 as in the middle and upper parts of the trunk ; in the wood it had 

 notably diminished in white -wooded trees, though still abundant in 

 hard-wooded trees, while plants with persistent leaves hardly held it 

 any longer save at the base of the stem and in the current year's 

 twigs chiefly on a level with the buds. He found that the starch 

 gradually passes from the wood into the liber, first from the medullary 

 rays, then from the w T ood parenchyma, and finally from the medullary 

 sheath and pith ; the rays of the young liber are the last to yield up 

 the vanishing starch. Apparently this absorption must needs, he 



