This exceptional book about the Natural History of Aquatic Insects is signed by the author and therefore quite unique.
Excerpt from The Natural History of Aquatic Insects:
The conditions of life in fresh waters are materially different from those afforded by the sea. The chemical difference between fresh and salt waters is of small importance in itself – so small that many animals have been able to adapt themselves gradually to a change from one to the other. A degree of saltness far greater than that of sea-water is perfectly compatible with animal life, as is shown by the fact that Crustacea and Insects are often found quite at home in brine-pits and vats. There are even a few animals, like the Salmon, which can pass suddenly from fresh water to salt, or from salt to fresh.