392 Collins.—The Structure of the Integumentary System of the 
Controls treated in precisely the same manner were set up in iodine. 
Blueing of the grain in the germinal region showed that the sealing was not 
effective in preventing the ingress of liquid. It was found that the swelling 
of the coats pi the grain broke the sealing, and thus paved the way for the 
entry of liquid. However, a difference in the rate of uptake was clearly 
obvious as a general result of the long series of experiments ; moreover, the 
possibility of the entry of liquid at special points in the germinal region, 
other than the micropyle, must not be overlooked. In this connexion it 
must be mentioned that at the germ end of the furrow, where the scutellum 
comes practically to the surface of the grain, there is no mass of cell-walls 
to hinder the passage of liquids once they have traversed the group of cells 
with yellowish contents. Frequently, evidence was obtained that penetration 
occurred at this point (see Figs. 3 and 4 B). 
(b) Uptake by germinal and apical portions of the grain compared. 
To secure, if possible, some further confirmation of the view put 
forward that the uptake of water is localized somewhere in the germinal 
region of the grain, recourse was had to the following indirect method : 
Individual grains were selected and weighed ; as soon as weighed, each was 
placed in distilled water contained in a numbered watch-glass with a cover. 
All were maintained at a temperature of % 2 ° C. At the end of each hour 
a grain was taken, dried externally, and weighed. It was divided into two 
portions by a transverse cut just above the embryo. Each portion was 
weighed and then allowed to dry in the laboratory at the ordinary tem¬ 
perature, about 23 ° C. After drying, the portions were weighed again. In 
this way the increase of weight per hour of each portion of the grain was 
obtained, and a comparison instituted. 
The value of the uptake of water by the coverings was estimated by 
Brown at 8 per cent, of the dry weight, and this must be borne in mind 
when considering the results. The following tables give the results of 
a series of experiments, and a set of curves has been plotted to show the 
results of each series graphically. A second base line, representing the 
value of the uptake of water by the coverings, has been drawn in 
the graph series. 
Series I. Grains from one Ear. 
J \ r o . 
Dry 
Hrs . 
Wet 
0/ 
Germ Portion . 
°/ 
Apical Portion . 
e / 
Weight . 
Steep . 
Weight . 
IflC VCCLS € • 
Vo 
Dry . 
Wet . 
7o 
Dry . 
Wet . 
Vo 
1 
0*0670 
1 
0*0715 
0*0045 
6*7 
0*0250 
0*0275 
10*0 
0*0410 
0*0420 
2*4 
2 
0*0660 
2 
0*0720 
0*0060 
9 *o 
o'oi 55 
0*0185 
19*3 
0*0500 
0*0510 
2*0 
3 
0*0650 
3 
0*0710 
0*0060 
9*0 
0*00975 
0*0125 
22*0 
0*05425 
0-0570 
5 -o 
4 
0*0690 
4 
0*0765 
0*0075 
io*8 
0*0120 
o*o 160 
37*5 
0*0560 
0*0590 
5*3 
5 
0*0660 
6 
0-0755 
0*0095 
14*4 
0*0160 
0*0220 
37*5 
0*0490 
0*0520 
5-7 
6 
0*0640 
7 
0*0730 
0*0090 
14*0 
0*0175 
0*0230 
3 i -4 
0-0455 
0*0485 
6-5 
7 
0*0635 
8 
0*0735 
O’OIOO 
i 5'7 
0-0155 
0*0220 
4 I# 9 
0-0475 
0*0500 
5.2 
8 
0*0665 
9 
0*0765 
0*0100 
15*0 
0*0195 
0*0255 
30*7 
0*0460 
0*0490 
6-5 
9 
0*0680 
11 
0*0800 
0*0120 
7*6 
0*0240 
0*0320 
33*3 
0*0435 
0*0470 
8*o 
10 
0*0610 
12 
0*0715 
0*0105 
“17*2 
0*0180 
0*0250 
38*8 
0*0420 
0*0455 
8*3 
11 
0*0640 
■ 24 
0*0825 
0*0185 
28*9 
0*0225 
0'0325 
44*4 
0*0405 
0*0490 
20*9 
12 
0*0675 
2 5 
0*0865 
0*0190 
28*1 
0*0215 
0-0320 
48*8 
0*0455 
0*0530 
16*4 
