Amongst the polyps, sea-anemones, and jelly-fish, though we frequently find that there are distinct males and females, there is no courtship. This is connected with the fact that, like plants, they are (excepting the jelly-fish) fixed and immobile. The male cannot "court" the female, because neither of them can approach the other. I once saw in the aquarium at Naples a sudden and simultaneous discharge of a white cloud, like dust, into the water from half the magnificent sea-anemones fixed and immobile in three large tanks. The cloud consisted of millions of the small "mating cells," and were thrown off by the males. They were carried far and wide by the stream running through the tanks. In the sea such a discharge would be carried along by currents, and might fertilize egg-bearing sea-anemones of the same species growing a mile or two away. It is when we have to do with actively moving animals that "courtship" comes into existence. It has many features and phases, which comprise simple discovery of the female and presentation of himself by the courting male; attempts to secure the female's attention, and to fascinate and more or less hypnotize her, by display of brilliant colours or unusual and astonishing poses or movements (such as dancing) on the part of the male; efforts of the male to attach the female to himself, and deadly, often fatal, combats with other males, in order to drive them off and secure a recognized and respected solitude for himself and his mate. The courtship of many insects, crustaceans, molluscs, fishes, reptiles, birds, and mammals has been watched and recorded in regard to these details. Naturally enough, it is in the higher forms, the birds and the mammals, that there are the most elaborate and intelligible proceedings in regard to the attraction of the female. But when we compare what birds or, in fact, any animal, does with what man does, we must remember that man has, as compared with them, an immense memory, and has also consciousness. All other animals are to a very large extent mere automata, pleasurably conscious, perhaps (in the higher forms), of the passing moment and of the actions which they are instinctively performing, but without any understanding or thought on the subject. They cannot think because, though some of them are endowed to a limited extent with memory, they have not arrived at the human stage of mental development when consciousness takes account of memory, a memory of enormously increased variety and duration.