52 
Proceedings of the Royal Society of Edinburgh. [Sess. 
Immersion in Sea-Water. — The stock of sea-water (obtained from 
Millport) had a chloride content equivalent to 3*25 grammes of NaCl per 
100 c.c. Being perfectly clear to the eye, it was not filtered. Eight 
experiments were carried out (on four males and four females, all medium- 
sized). The individual survival periods were 35 (bis), 51, 52, 58, 65, over 
83 (bis) days. Sex had no particular influence on the time of survival. 
There was no appreciable change in the external appearance of the dead 
animals. 
These survival periods are greatly in excess of those recorded by 
Stewart. The experiments prove that Ligia can live for weeks and even 
months in sea- water ; secondly, that it can endure fasting for an equally 
long period of time. 
Immersion in Half Sea-Water. — Experiments were carried out on 
five medium-sized animals (sex undetermined) and on one large male. 
The periods of survival were 16, 18, 24 (large male), 34, 37, 42 days. Only 
in one case (that of the 37 days’ survival) was there any appreciable change 
at death ; this consisted in swelling of one solitary internal gill-lamella. 
It is to be noted here that even the longest period of survival in half 
sea-water is much less than the average period of survival in full sea- water 
as determined in the preceding experiments. Reduction of the salinity 
of the sea-water to one-half distinctly diminishes the survival period. 
Immersion in Quarter Sea- Water. — Six medium-sized animals were 
used (sex not determined). The periods of survival were 3, 5, between 
7 and 9 (bis), 9, 15 days. Two of the animals showed marked oedema 
of the body (see below) before death. One of these, recorded above as 
surviving 9 days, when almost in articulo mortis was replaced in sea- 
water, where it slowly recovered power of movement ; by next day the 
oedema had subsided : the animal continued to live in good health in 
sea-water for a week, after which it was removed to be fed for another 
experiment. Swelling of internal gill-lamellae was noted in both these 
oedematous animals, but not in any of the others. 
Immersion in Distilled Water. — The number of experiments reached 
beyond one hundred and fifty. This larger number was found necessary, 
because with a given batch of animals selected at random the survival- 
periods (short compared with those already recorded) were found to vary 
greatly. After the first 8 or 9 hours individual animals began to die, and 
this process might continue for at least 36 hours thereafter. The aim at 
first was to establish an average result; it was soon directed, however, 
towards the settlement of the condition or conditions responsible for the 
variability. 
