204 
Tuttle . — Induced Changes in Reserve 
Material which has been inside for two days shows a starch reaction in 
all parts of the leaf. At the end of four days the cells are quite crowded 
with starch, but the amount increases until the seventh or eighth day (Fig. i), 
after which time the starch content seems to remain constant. 
The starch in all cells is present in a very finely divided state and the 
individual grains exhibit Brownian movement to a marked degree. 
* IG. I. Cross-section of Linnaea leaf, showing starch in material exposed to higher temperature 
for one week. Section treated with chloral hydrate and iodine. 
Fig. 2. Horizontal section of Linnaea leaf, showing starch in epidermal cells. The material 
had been exposed to higher temperature for one week. Section treated with chloral hydrate and 
iodine. 
It is interesting to note the large amount of starch present in the 
epidermal cells of material undergoing conversion (Fig. 2), as none is found 
there during the summer when the starch is being formed as a product of 
photosynthesis — this apparently suggesting that the starch has arisen by 
conversion of oils and fats which are abundant in the epidermis during the 
