I well remember the pleasant evening on which I first made the personal acquaintance of this amazing amazon. It was at Munich, and in the house of a celebrated naturalist, in whose garden an agreeable assemblage of poets, professors, and their wives, sauntered in the light of a setting sun, breaking up into groups and _têtes-à-têtes_, to re-form into larger groups. We had taken coffee under the branching coolness of trees, and were now loitering through the brief interval till supper. Our host had just returned from an expedition of some fifty miles to a particular pond, known to be inhabited by the Apus. He had made this journey because the race, although prolific, is rare, and is not to be found in every spot. For three successive years had he gone to the same pond, in quest of the male: but no male was to be found among thousands of egg-bearing females, some of which he had brought away with him, and was showing us. We were amused to see them swimming about, sometimes on their backs, using their long oars, sometimes floating, but always incessantly agitating the water with their ten pairs of breathing legs; and the ladies, gathered round the jar, were hugely elated at the idea of animals getting rid altogether of the sterner sex--clearly a useless incumbrance in the scheme of things! The fact that no male Apus has yet been found is not without precedent. Léon Dufour, the celebrated entomologist, declares that he never found the male of the gall insect (_Diplolepis gallæ tinctoriæ_), though he has examined thousands: they were all females, and bore well-developed eggs on emerging from the gall-nut in which their infancy had passed. In two other species of gall insect--_Cynips divisa_ and _Cynips folii_--Hartig says he was unable to find a male; and he examined about thirteen thousand. Brogniart never found the male of another entomostracon (_Limnadia gigas_), nor could Jurine find that of our _Polyphemus_. These negatives prove, at least, that if the males exist at all, they must be excessively rare, and their services can be dispensed with; a conclusion which becomes acceptable when we learn that bees, moths, plant-lice (_Aphides_), and our grotesque friend _Daphnia_ (Fig. 9) lay eggs which may be reared apart, will develop into females, and these will produce eggs which will in turn produce other females, and so on, generation after generation, although each animal be reared in a vessel apart from all others.