Biological Papers. 105 



The leaves were examined every half-hour, beginning at four 

 o'clock. At this time the cells were crowded with starch, especially 

 around the sieve-tubes. The outer palisade cells, next to the epi- 

 dermis, showed a decrease of starch. At 4 : 30 most of the starch 

 had gone out of the palisade cells and there was a considerable re- 

 duction in all other cells. At five o'clock starch was left only in 

 the sieve-tubes and a little in the cells bordering them. At 5 : 30 all 

 the starch had gone from the leaf. At six o'clock starch began to 

 appear again in the palisade cells. 



Thus it will be seen that starch disappeared first from the palisade 

 cells and reappeared there first. 



