228 
STRANGE DWELLINGS. 
CHAPTER XX. 
SUB-AQUATIC NESTS. 
INVERTEBRATES. | 
A Pool and its wonders— The Water Spider — Its sub-aquatic nest — Convey- j 
ance of air to the nest— The diving-bell anticipated — Character of the air in j 
the nest — Mr. Bell’s experiment upon the Spider — Life of the Water Spider— 
The Hydrachna — The Caddis Flies and their characteristics— Sub-aquatic !j 
homes of the Larva — Singular varieties of form and material — Life of a 
Caddis — Description of nests in my own collection — Fixed cases, and modifi- 
cation of Larva — Singular materials for nest-building — Different species of 
Sabella — The Silkworm Amphitrite — The Terebell^e and their sub- 
marine houses — The Caddis Shrimp — Remarkable analogy. 
When I was a very little boy, I was accustomed to spend much 
time on the banks of the Cherwell, and used to amuse myself 
by watching the various inhabitants of the water. Animal life 
is very abundant in that pleasant little river, and there was one 
favourite nook where a branch of a weeping- willow projected 
horizontally, and afforded a seat over the dark deep pool, one 
side of which was abrupt and the other sloping. 
Here the merry gyrini ran their ceaseless rounds, and the i: 
water-boatmen rowed themselves in fitful jerks, or lay resting in j 
a contemplative manner on their oars. Now and then an un- : 
lucky insect would fall from the tree into the water, and then 
uprose from the dark depth a pair of dull eyes and a gaping 
mouth, and then, with a glitter as of polished silver, the dace J 
would disappear with its prey. In the shelving part of the pool 
the caddis-worms moved slowly along, while the great dyticus 
beetle would rise at intervals to the surface, jerk the end of his 
tail into the air, and then dive below to the muddy bottom. 
This spot was much favoured by the nursemaid, for she had no 
trouble in watching me, as long as I could sit on the branch and 
