176 Part I11.—Twenty-fourth Annual Report 
exhausted by his onerous task and prolonged fast. That this was not 
entirely due to these causes was shown when the supply of water to the 
tank was increased, and when it was directed to his corner. After a 
refreshment of this kind he moved round about with vigour, energetically 
spouting water on the eggs and fanning them with his fins. 
Towards the end of the month he took a mussel occasionally and 
swallowed it. This was first noticed on the 26th, and on some days he 
ate as many as five; any excess he carried off and ejected, as before; and 
at the beginning of May he was as alert, active, and pugnacious as ever. 
On one day at this time I dropped on the top of the egg-mass a little 
commcn swimming-crab, about 1; inches in breadth, which, apprehend- 
ing danger, clung tightly in one of the snout-depressions on the surface 
of the eggs. It was amusing to watch the lumpsucker ineffectually trying 
to rout him from the hollow in which he had taken refuge, the blunt 
snout of the fish preventing a hold being got on the crab. He tried again 
and again to dislodge or seize the crab. At last the crab turned partly 
on its side, and extended its widely-opened. chele as if to defend itself, 
which gave the fish its opportunity. It seized the crab in its mouth and 
swam off with it to the furthest corner of the tank, where it dropped it. 
Early in the experiment the outer fire-clay pipe was removed and an 
apparatus fitted up to the overflow, so that all the water leaving the tank 
passed through two boxes with fine silk-gauze bottoms. This was to 
retain the larval lumpsuckers when they issued from the eggs. The 
first of these was got on 5th May, 43 days after the eggs were deposited 
and fertilized. The daily temperature of the water during this period 
may be seen by reference to the tables on pages 113 and 284. When 
the eggs were spawned it was 42°5°F; in April it varied from 41°5° 
to 46° ; and at the end of the month was 43:7°F. and 45°F., rising to 
44°6° and 47°F. in the first week of May. 
For the first few days after the 5th, the tadpole-like larval lumpsuckers 
were found in small numbers in the overflow-filter every morning, and 
they slowly increased in numbers. They were very active, swimming 
with great rapidity by a lashing movement of the tail, a large yolk 
containing an oil globule at the right side being conspicuous. 
At this time, as I have mentioned, the male parent was most assiduous 
in his attention to the eg¢-masses, redoubling his activities both in fanning 
and “blowing” upon the eggs. He ate mussels sparingly, sometimes 
fasting for a few days, and carrying off and ejecting the proffered food. 
He also continued to chase the other male and drive off intruders. 
Up to the 22nd May, or almost exactly two months from the time the 
eggs had been spawned, and seventeeen days after they had begun to 
hatch, the conditions described continued. The young lumpsuckers were 
appearing in greater numbers, but still not in such abundance as one 
might have expected. The largest number was about two or three 
hundred ina day. They were also to be seen adhering to the glass front 
of the tank, and numbers were thus accounted for. None were observed 
on the back of the male, a habit sometimes attributed to them. 
It was now noticed, however, that many of the larval lumpsuckers were 
dead and white, and these were also seen floating in the water. On 
examination, it was found that the condition of the tank was unsatisfac- 
tory; it was obviously rather dirty from an accumulation of weed and 
refuse, and had probably too many occupants for the experiment, and 
when the egg-masses were examined their lower parts were found to be 
black and fetid, a circumstance that explained the presence of the dead 
and whitened young lumpsuckers. Clearly the aération had not been 
sufficient for the interior of the egg-masses, The supply of water to the 
