The Causes of the Zoning of Brown Seaweeds. 63 
very variable, though the mean values seem to show that, apart 
from the removal of the paraphyses, waxing has very little effect 
on the dehiscence. 
The means of sixteen experiments with Fucus spiralis (in which 
waxing removes some of the paraphyses) were:— 
$ Waxed = 7 bundles liberated. Check— 13 bundles liberated 
? Waxed — 63 „ „ Check = 166 „ „ 
With Fucus serratus (in which waxing does not remove the 
paraphyses) the results were : 
$ (means of 10 experiments) waxed = 16 bundles liberated. 
Check =13. 
? (means of 4 experiments) waxed =119 bundles liberated. 
• Check = 115. 
The second set of experiments was carried out in London in 
November and December, on material which was obtained from 
Mersea Island, Essex. The liquid used was water, and this was 
selected for two reasons. First, it is not solid at ordinary tem¬ 
peratures, and so cannot block up the conceptacles; and, secondly, 
the hairs can be removed before exposing the receptacles. Two 
twin receptacles were put into two test-tubes; one was washed 
and covered with distilled water, the other similarly treated with 
sea-water. The test-tubes were put into larger tubes and the tops 
padded with cotton wool. These air jacketed tubes were put into 
No. 
MALE. 
FEMALE. 
No. 
MALE. 
FEMALE. 
Iced. 
Check 
Iced 
Check 
Iced 
Check 
Iced 
Check 
I. 
4 
14 
102 
168 
VI. 
5 
15 
34 
51 
II. 
16 
22 
70 
106 
VII. 
9 
9 
54 
48 
III. 
3 
7 
55 
81 
VIII. 
8 . 
13 
114 
299 
IV. 
4 
7 
61 
89 
IX. 
7 
11 
44 
63 
V. 
3 
5 
15 
31 
X. 
9 
14 
53 
69 
the same freezing mixture, so that whatever effect the cold had 
upon the seaweeds should be shared equally by both. The distilled 
water froze into a solid mass; but the sea-water, owing to its 
higher osmotic pressure, did not freeze so readily; and when it did 
freeze the ice formed in crystals and not in a solid mass. It was 
found advisable, however, to melt any crystals when they were 
formed; as the mere solidification of the water round them is 
