I IO 
NATURE NOTES 
relationships, and were content to see the colony grow, and to 
watch the movements of the graceful living fringe through a 
pocket lens. 
For some days after the introduction of the new water-beetle 
all seemingly went well, until one morning the triton — “ Pa,” 
we called him — failed to appear to take his meal. The cover 
of perforated zinc happened to be slightly disarranged and we 
concluded that he had taken this chance to escape, and expected 
at some future date to find his desiccated remains in some 
isolated corner; but expected in vain. Next the two smooth 
newts were missing. Again we blamed the cover and took 
means, now that the stable was empty, to so fix the perforated 
zinc as to prevent like escapes in the future. 
A few mornings later we noticed a number of snails crawling 
up the glass out of the water. Some had reached and were 
resting on the underside of the perforated zinc, and others were 
poised on some floating pieces of cork. We put them all back 
into their natural element, and as we did so, noticed our dark- 
coated giant hanging head downwards, his tail just protruding 
above the surface of the water, taking in a new supply of air. 
We gave him a playful touch and he dived hurriedly, taking 
a big silvery bubble with him. The following morning at break- 
fast time, many of the snails seemed again bent on a pilgrimage, 
and as we wondered, we became aware of an ominous “crunch,” 
“crick,” “crunch.” We removed the cover and looked in, and 
there was the false Hydrophilus, revealed to us as the voracious 
Dytiscus. He had firm hold of a large Lininaa with his front 
prehensile legs, and in a most systematic manner was breaking 
the shell with his mandible, as a parrot snaps the shell of a 
Brazil-nut with his beak. After he had gorged the juicy 
mollusc, only the columella, with some jagged portions of the 
shell adhering, was left. The repast over, he all unconcernedly 
turned a somersault and ascending, tail uppermost to the surface 
of the water, took a rest and airing of fully two hours’ duration. 
When we investigated matters we found the sand at the bottom 
of the aquarium covered with a layer of shell remnants. Was 
it a sense of danger made those other snails try to seek a place 
of safety? We gave them credit for this wonderful instinct of 
self-preservation and put them with our gold-fish, where they 
showed no further signs of disquietude. 
The snails, which appeared satisfied with their lot, we left 
with Dytiscus. We had no wish to starve the warrior, only, 
had we been awake to his real character, we should have pro- 
vided for him differently. After all, Dytiscus is not the only 
creature in the world with a partiality for living molluscs. We 
gave him some small pieces of fresh English beef, and so as to 
be able to remove any discarded portions, tied them on a thread. 
He hugged one small piece and sucked the juices from it, and 
then as though suspicious of the offering being other than home 
produce, treated the remainder with withering disdain. But 
we were both surprised and angry when we discovered that the 
