102 THE BOTTOM. 



going all round. The glass is set in grooves in the 

 slate and wood, and fastened with white-lead putty. 

 I first stocked it before the emanations of the putty 

 &c. had sufficiently gone off; and hence the plants and 

 animals died almost as fast as they were put in, rarely 

 surviving the first night, although the water was 

 renewed from the sea once and sometimes twice a day. 

 The Mullet-fry and a few Actinias alone survived the 

 experiment, which was continued for a week. 



At the end of that time I emptied it, had it carefully 

 cleansed and rinsed with fresh water, and allowed it 

 to remain in the open sun and air for a week, when I 

 judged all smell from the paint had ceased. 



I now refilled it. The mode in which this was done 

 was as follows. First I laid on the bottom a stratum 

 of stiff blue clay, varying in thickness from two inches 

 to half-an-inch. On this a layer of small pebbles, 

 coarse gravel, fine gravel, and sand, was put, so as to 

 afford varieties of bottom. Then pieces of rock were 

 carefully put in, so selected and arranged as to make 

 arched passages and overhanging shelters, with one 

 mass rising pyramidally to within a few inches of the 

 surface. 



The sea- weeds, attached to fragments of stone, 

 were now introduced ; the larger and heavier on the 

 bottom, the smaller and more delicate laid on the 

 ledges of the rocks, or inserted into the crevices. 

 Among the former were a large tuft of Furcellaria 

 fastigiata, two of Ghondrus crispus, two of Rhody- 

 menia palmata, one of Dictyota dichotoma, a small 

 plant of Fucus serratus, one of Laminaria digitata 

 (young), two tufts of Padina pavonia, and several 



