1909.] NATURAL SCIENCES OF PHILADELPHIA. 69 



(1) Forsythia viridissima. — The iodine test showed the pith cells 

 crowded with starch, as also the cortex cells between the bast fibers, 

 as also the medullary ray cells. Fehling's test gave no reaction. 



(2) Magnolia conspicua. — On treating the sections with iodine 

 starch was found in the medullary ray cells and not any in the cortex. 

 Fehling's test for sugar gave no reaction. 



(3) ^Esculus hippocastanum. — Starch occurs in the protoxylem 

 region, in the inner part of the medullary rays. No starch was found 

 in the cortex cells and no reaction was produced with Fehling's solu- 

 tion. 



(4) Populus monilifera. — The iodine test showed the presence of 

 starch in the cortex. Fehling's test for sugar gave no result. 



(5) Liriodendron tulipifera.— Starch is present in the younger 

 and older portions of the stem in the cortex cells. No sugar reaction. 



(6) Salix babylonica. — Iodine showed the presence of starch in 

 the cortex cells and medullary ray cells. No starch was found in the 

 pith. Fehling's sugar test was negative. 



(7) Tilia Americana. — Small starch grains were found in the cor- 

 tex of a one-year old stem. No starch was seen in the cortex of old 

 stems. In water the sections became strongly mucilaginous. Feh- 

 ling's solution gave no reaction. 



(8) Quercus PALUSTRis. — Starch was found in the pith, medullary 

 ray cells and in the wood-parenchyma cells. No starch was detected 

 in the cortex. Fehling's solution gave no starch reaction. 



• As far as these microscopic studies throw light upon the state of 

 the plant's preparedness, they seem to support the view that the more 

 prepared a plant is and the more responsive its protoplasm is to the 

 influence of external conditions the earlier is its response. For the 

 response of Quercus palustris with deep-seated starch is much more 

 sluggish than the response of the twigs where the starch occurs in the 

 cortex. This relationship of response to the position of the reserve 

 food should not, however, be pushed too far, as the protoplasm of the 

 twigs and that of the cells of the preformed buds may be influenced 

 without any transformation of the reserve supplies of food. We do 

 find, however, a sequential development of the buds and, as far as the 

 experiments go to show, that sequential development is not disturbed 

 by the chemicals that are used. The course of bud development, 

 therefore, depends upon the state of preparedness of the twig and bud, 

 and not on the environmental conditions which surround the plants. 

 Heat is the great factor which determines the opening of the buds. 

 If the plant has the requisite supply of moisture, heat will accelerate the 



