240 = TREUBIA VOL. Il, 2—4. 
The three kepala timah from the last little table given above, which 
had been transferred from water of a salinity of 27.8 °/, into water of a 
salinity of 52.4°/,, or of 62.9 °/,, tried by all possible means to get out 
of the concentrated solution, before the lethargic condition set in. They 
repeatedly swam slantingly downward against the glass bottom of the 
aquarium trying to escape into the depth. They would also jump clear of 
the water and frequently landed outside the aquarium on the dry. 
It already follows from what I stated above, concerning the transfer- 
ring of these little fish from distilled water to sea-water of a salinity of 
33.4 Jo, that the lethargic state is not always followed by death in the 
kepala timah. In proportion as the difference of salinity is greater, between 
the water in which the animals first lived and that to which they were 
subsequently transferred, the lethargic state is developed in a more marked 
degree. If this difference of salinity becomes too great, the lethargic stage 
is followed by death, but as long as the difference is not so wide, the 
animal re-awakes pretty soon from its lethargy and soon after behaves 
quite normally again. When the lethargic symptoms only develop to a 
slight degree, the occipital spot does not grow dim; this happens only in 
bad cases like those described above, which were lethal. 
Soon after the transference of kepala timah from water of a lower 
into water of a higher salinity, the little animals appeared to be coated 
with a white wax-like layer, especially at the mouth, tail and belly-side 
of the body. I have not tried to ascertain to what this phenomenon was 
due, but one is inclined to think of an increased mucous secretion of the skin. 
In conclusion | ascertained how long the two animals from the last 
foregoing table, which after 824 hours had got into fishpond water of 
a Salinity of 60 °/o, could stand the gradually continued concentration of 
this water by evaporation. With a view to this the aquarium that was 
their abode was occasionally exposed to the sun and all the time as much 
as possible to draughts of air. The result was that 15 days after this had 
oegun one of the animals sprang out of the aquarium then standing in the 
sunlight, which was not perceived at once, so that the animal met its death 
on the dry, I have already remarked before that I also observed this jum- 
ping out of the water, on the kepala timah being suddenly cast into water 
whose salinity deviated considerably though not too much from that of the 
water they had been living in before being transferred. 
The aquarium with the remaining kepala timah was now covered over 
with metal-gauze so as to prevent the animal from leaping out. A couple 
of days later there were signs that also this little fish began to fare worse, 
It hardly ate and became ever less mobile, till at last it just floated about 
listlessly at the surface, hardly moving its fins. At this stage, as has been 
described before, part of the back emerged from the water whilst the edges 
of the caudal fin and of one of the pectoral fins assumed a shrivelled 
and withered appearance. 
