66 Part ITT. —Twenty-third Annual Report 
Fullarton adopted the method of keeping the berried females in con- 
finement, in an open pond, until the eggs hatched; but in his experi- 
ments carried out in 1895 the larve were allowed to escape to the sea as 
they were hatched. In the present case the young lobsters had to. be 
retained. The arrangement was as follows The berried hens, fourteen 
in number, were kept in a wooden tank measuring about 8 feet by 4 feet 
6 inches by 2 feet deep. The water supply entered at the bottom of 
the box, and the outflow took place from the surface of the water. The 
overflow water was led into the hatchery and distributed into the hatching 
apparatus. As the little lobsters hatched out they were carried down to 
the hatchery and caught and detained in the hatching boxes. 
In order that a large number comparatively of lobsters be kept in a 
small area, it is necessary that they each be provided with a hole or pen 
for shelter. The wooden tank in which the adults were confined 
was prepared in the following manner. A plank of wood about 7 
inches wide was hinged by means of large fencing staples to the side 
of the wooden tank. When horizontal in position it was about 4 
or 5 inches above the bottom. ‘The space beneath this shelf was 
divided off by means of bricks set on edge into as many compartments 
us were required; in this case seven. The shelf rested on the bricks, 
and when the tank was filled it was kept down by a suitable weight, 
some stones or bricks. One shelf was put on each long side. This 
arrangement permitted of ready examination of the lobsters, as when 
the superincumbent stones were removed the shelf floated up, revealing 
the lobsters. They remained there, then, in apparently suitable con- 
ditions. Each lobster stuck to its pen, its body hid by the shelf, and its 
projecting antennz alone betraying its presence. Only one lobster died 
from injuries received through fighting with the other inhabitants of the 
tank. The large chelz were not tied. 
The young hatched out in batches. The eggs of one female do not all 
hatch simultaneously, but over a period. In two cases recorded by 
Herrick, a week elapsed from the time the first larva appeared until all were 
hatched out. Fullarton found the time necessary for hatching a single brood 
varied from a week to three weeks, or even longer, The aeration of the 
eggs attached to the abdominal feet of the female is assured in the 
following manner. The lobster is seen every now and then with its 
abdomen stretched out to its full extent and resting on the inturned edge 
of the telson. The swimmerets are meanwhile gently waved backwards 
and forwards, in this way aerating the eggs and tending to cleanse them. 
When the eggs are ready to hatch this facilitates the escape of the larve. 
This action was noticed by Coste. The hatching of the lobster eggs at 
Brodick, Fullarton states, occurred in July, August, and September, with 
a maximum in August. 
The first young lobsters were observed in the Laboratory, Bay of Nigg, 
on July 11th; they had then reached the hatching apparatus. They 
apparently hatch during the night, as each morning there was a fresh 
addition to the stock. The little lobsters were in the first zoéa stage 
(fig. 66). They were kept in boxes having sieve bottoms, which were 
placed in the top compartments of a hatching apparatus. They measured 
about 1 foot by 1 foot by 1 foot, and were painted black. They received 
light from above only. The number of larve kept in one box varied, 
but not more than twenty were knowingly confined together. They were 
kept in the top compartments in order that they might obtain a share of 
the food that was being brought in by the water supply, e.g. copepoda, 
diatoms, and larve of invertebrates. The water was not filtered. It flowed 
into the box by a spout and out by the sieve bottom, the arrangement 
which is followed in hatching the eggs of plaice and cod. 
De ee ee eee re 
