Page:The Book of the Aquarium and Water Cabinet.djvu/154

142 cost of its life. I have several times introduced the Hydrachna into my jars of Nepa, but have never yet witnessed the parasitic deposit of the eggs. In confinement, the Nepa is the least hardy of any creature in the collection, if the sun strikes the jar it perishes, and it will not live long unless it has means of occasionally leaving the water—hence a broad jar should be used for it, and a small piece of pumice stone should be floated in it, to form an island on which the insects may take refuge.