2j8 Read. — A Study of the Enzyme- secreting Cells in the 
at first the cytoplasm of the secreting-cells contains fine, granular proteid 
material, which shows an affinity for basic stains. The nuclei of these cells 
contain finer granules, which stain differently from those in the cytoplasm 
and disappear much sooner. With the high power they can easily be 
distinguished from the chromatin. The amount of chromatin is small in 
the earliest stages, but the nucleoli are quite prominent. 
At the beginning of the second day of activity the cytoplasm is densely 
filled with granular material, which is distributed on the cytoplasmic reticu- 
lations. A comparison of Figs. 2 and 3 will show the relative increase in 
size of the cell during the first day’s activity. From this time forward there 
is a constant depletion of the granules of the cytoplasm, accompanied by a 
slow elongation of the epidermal cells. The nuclei are almost invariably 
nearer the proximal end of the cell. After two days of activity, one can 
notice that part of the starch of the endosperm has disappeared. In the 
nuclei of the epidermal cells there are two noticeable changes — a continued 
increase in the amount of chromatin and a decrease in the size of the 
nucleolus, which from this time forward is very inconspicuous. 
The processes described above continue without much variation until 
the endosperm is exhausted. On the third or fourth day the nuclei move 
from their position in the proximal end of the cell toward the centre, and on 
the fifth or sixth day are found in the distal end of the cell (Fig. 7). The 
cytoplasm is nearly free from granules on the tenth day, and now shows an 
affinity for acid stains. Just before the final dissolution occurs, the cyto- 
plasm of the epidermal cells becomes abundant and stains similarly to the 
nucleus. 
C. The Effect of Inhibited Growth upon the Secreting-Cells. 
Seedlings which had grown at a temperature of 23° C. for fifty hours, 
and whose roots had attained a length of 3 to 4 cm., were transferred to 
a temperature of 8-io° C., after having removed and fixed a number of 
scutella. When they had remained twenty-four hours at the low tempera- 
ture, the amount of growth shown by the roots was very small. At this 
time more material was removed and fixed in different killing fluids ; the 
remaining seedlings were then placed at a temperature of 20° C. for forty 
hours longer. At the expiration of this time the roots showed that growth 
was progressing normally again. The different lots of material were then 
sectioned and stained for microscopical study. 
The sections showed that the cells of the epidermal layer were in an 
active condition when transferred to the cold room. They were full of fine 
granules, which stained blue with Mann’s Eosin-Toluidin Blue. -The densest 
accumulation of granular material was in the distal end of the cells. The 
nuclei, which were in the proximal end of the cell, contained chromatin in 
