A YEAR ON THE WAR-PATH 
109 
with filmy air-bubbles, made them very pretty objects in the 
water. One day we noticed one of the beetles busy at work just 
under the surface of the water, seemingly trying to spin a spider’s 
web, and a few hours later the web had developed into a little 
silken oval-shaped nest, rather larger than a good-sized pea, and 
in this the beetle had deposited her eggs. 
Unfortunately the aquarium became slightly tilted, and this 
being unobserved till too late, the nest and its contents were left 
high and dry above the water, and spoilt. We cut open the nest 
and found that the eggs, which were glued together in great 
regularity, were quite withered. A small portion of the nest 
material placed under the microscope showed the silken threads 
of which it was composed, all meshed and netted together, some- 
what like the texture of our toilet sponges, only looser and 
coarser. A few days after the accident, a second nest was built, 
whether by the same beetle or not we hesitate to say. The 
family likeness is so close that it does not admit of much distinc- 
tion between individual members ; but, as if the fate of the first 
nest had conveyed a lesson, the second was built about an inch 
below the surface and attached to the glass as before. All went 
well for a few days and then a great blundering snail, a L itnncea, 
came browsing along, and clumsily pushing the dainty silken 
cradle before him detached it from its moorings. For a time the 
buoyant little ark floated on the surface ; but finally it became 
water-logged, and sank to the bottom of the aquarium, and we 
waited in vain for further development. The two beetles died 
shortly after nest-building, as though nest-building consummated 
their life-work. This may be so, but we do not know. The 
renewal of an acquaintance with this interesting family of nest- 
building beetles we had often desired, so when our friend presented 
us with a giant Hydvophilus, we were more than gratified. 
The aquarium in which we placed him was dense with water- 
weed and rich with microscopic organisms. We should hardly 
like to say how many districts and how many ponds the life in 
that aquarium represented, for its contents had been the gather- 
ing of years. Besides microscopic specimens, there were snails 
of all sizes belonging to the genera Limncea and Planorbis, some 
pearly white bivalves of the genus Sphccvium , caddis larvae, water- 
hogs ( Asellus ), water-scorpions ( Nepa ), leeches, small red worms 
and other creatures. 
A triton and two smooth newts had been then quite lately 
introduced, and all three were very tame and would come round 
to us to get their food when we tapped on the glass of the 
aquarium. 
On that side of the glass facing the setting sun was encamped 
a numerous colony of green hydras, the single parent of which 
we had brought from a stream bordering a grouse moor in Mid- 
lothian. On the Friday when we took the dipping in a specimen 
tube there was one hydra ; on the following Monday this had 
budded, and produced children and grandchildren to the number 
of seven. After this we gave up counting individuals, or hazarding 
