18 Proceedings of the Royal Society of Edinburgh. [Sess. 
on stimulation. Attempt at unflexing the abdomen of a normal animal 
causes violent efforts to prevent the unbending, and, should this be ac- 
complished, the animal is able to close the abdomen again. With an im- 
Results of Immersion Experiments — Females. 
Size in 
Centimetres. 
Number of Animals and Average 
Weight. 
Post. 
Inter. 
Pre. 
0-1 to DO 
... 
... 
IT to 2-0 | 
... 
4 
3 '5 grms. 
... 
2T to 3-0 | 
... 
5 
36 grms. 
... 
3T to 4 0 | 
... 
3 
13 ‘2 grms. 
1 
7'0 grms. 
4T to 5-0 | 
1 
20'0 grins. 
6 
20'6 grms. 
3 
2 P0 grms. 
5d to 6-0 | 
2 
34*0 grins. 
3 
33 O grms. 
6 
39*2 grms. 
6T to 7-0 | 
1 
49 ’0 grms. 
3 
50'0 grms. 
7T to 8-0 
... 
... 
... 
Extreme Limits of 
Period of Survival.* 
Average Duration 
of Survival.* 
Post. 
Inter. 
- 1 
r 
H 
h 
i 
h 
15 
4.45 
to 
8.45 
3.5 
to 
11.0 
4.0 
to 
11.0 
9.0 
to 
14.35 
11.0 
to 
14.30 
11.30 
Pre. 
1 
Post. 
3.15 
4.30 
to 
7.30 
3.20) 
to f 
9.30 J 
7.20 
to 
8.15 
7.0 
4.15 
Inter. 
6.0 
7.18 
9.50 
11.30 
12.45 
11.30 
Pre. 
3.15 
6.0 
’.40 
.25 
* The time is in hours and minutes. 
mersed animal the response is feeble, and, once opened, the abdomen remains 
so ; similarly, irritation of the oral margin and separation of the third 
maxillipedes produces no response. The righting reflex is also lost, i.e. the 
reflex which turns the crab on its ventral surface when it has been placed 
on its back. Respiration, as indicated by the movement of the scaphog- 
nathite, had already ceased, but on post-mortem examination the heart 
was found to be still acting. 
(Edema. 
Some time before death, flexion of the limbs commenced, causing the 
animal to be gradually raised from the ground. This continued, and, being 
