1917-18.] Period of Survival of Shore-Crab in Distilled Water. 17 
half is imminently pre-moult. Post-moult animals harden rapidly and in 
a few days acquire inter-moult characteristics, including longer survival. 
A post-moult Ligia, therefore, being practically inter-moult posteriorly and 
Results of Immersion Experiments — Males. 
Number of Animals and Average 
Extreme Limits of 
Average Duration 
Size in 
Weight. 
Period of Survival.* 
of Survival.* 
Centimetres. 
Post. 
Inter. 
Pre. 
Post. 
Inter. 
Pre. 
Post. 
Inter. 
Pre. 
OTtol-oj 
6 
0’68 grms. 
} - 
/ 
... | 
1.10 
to 
2.40 
\ 
j- 
... 
2.23 
IT to 2-0 | 
... 
16 
3'1 grms. 
> 
J 
■d 
2.10 
to 
8.30 
1 
J- 
... 
6.9 
... 
1 2T to 3-0 | 
I 
1 
? grm. 
7 
4 -4 grms. 
* 
1 - 
4.0 j 
i 
4.0 
to 
15 10 
1 
y 
4.0 
10.19 
... 
3*1 to 40 | 
11 
10 - 2 grms. 
} - 
| 
... | 
5.0 
to 
12.30 
1 
... 
10.18 
... 
j 
4T to 5-0 | 
2 
20'0 grms. 
7 
20 - 0 grms. 
i 
i - 
( 4.50 
s to 
( 8.30 
7.0 
to 
16T5 
i "■ 
6.40 
10.15 
... 
5T to 6-0 i 
I 
2 
29’2 grms. 
7 
49 ‘75 grms. 
( 4.8 
s to 
( 5.5 
10.50 
5 5 ‘8 grms. 
to 
14.50 
j-7.30 
4.36 
12.40 
7.30 
6T to 7-0 | 
8 
56 A grms. 
4 
63 U grms. 
( 
5.45 
5.15 ) 
. . . 
-1 
to 
16.30 
to / 
7.45 ) 
13.33 
6.8 
c 
Q 
*7 
f 
... v 
l 
10.20 
5.301 
7T to 8'0 1 
i 
o 
99 '0 grms. 
i 
88T grms. 
to 
20.0 
to > 
11.0 J 
14.13 
7.20 
* The time is in hours and minutes. 
becoming rapidly so anteriorly, corresponds to an early inter-moult con- 
dition of Carcinus. 
Behaviour during Immersion. 
The behaviour of the crabs during immersion was moderately uniform, 
although some were more active than others. The first noticeable effect 
was lessened activity, accompanied by weaker and slower movements. The 
reflex mechanism became gradually impaired, resulting in loss of response 
VOL. xxxviii. 2 
