It is a common belief that æsthetic appreciation ceases as soon as we sit down to the microscope. There is the magnificent blue Strait of Messina. Your eye, embracing its whole length, drinks in its beauty in deep draughts. What will your microscope make of it? Its field can only take in a single drop of water, and this does not grow more blue when you thus analyse it. Let science go further afield: this is the land of beauty. All those doctrines of histology, embryology, and so on, built on the microscope, are thought to be poles removed from æsthetic enjoyment. They dissolve everything—man’s soft, white skin, the perfumed leaf of the rose, the bright wing of the butterfly—into “cells.” It is mere ignorance to talk in this way. Nature’s beauty is by no means so thin a covering that the microscope must at once pierce through it. Rather does it reveal to us in incalculable wealth a whole firmament of new stars, a new world of beauties, if we choose the right way to see them. Haeckel did choose the right way. At his very first dips into the harbour of Messina, in October, 1859, he got certain curious lumps and strips of jelly. The local fishermen called them _ovi di mare_ (sea-eggs). It was, in fact, natural enough to regard these inert creatures as strings of mollusc-eggs, when their real nature was unknown. But our young student already knew what they were. They were social _radiolaria_. [Illustration: A RADIOLARIAN. (_Lychnaspis miranda._) ] The word “radiolarium,” from _radius_ (a ray), means a raying or radiating animal. It is difficult for the inexpert to imagine the structure of one of these creatures. He must first put entirely on one side all the features that he usually associates with an “animal.” The radiolarian lives, moves, has sensations, breathes, eats, and reproduces, but in a totally different way from that we are accustomed to see. Its body consists essentially of a particle of homogeneous living matter. There is merely a firmer nucleus in the centre of it, and the soft gelatinous matter is thickened at the surface to form a kind of capsule. Otherwise there is no trace of any real “organ.” The little blob of jelly eats—but it has no stomach; it eats with its whole body, its soft, jelly-like substance closing entirely over particles of food and absorbing them. It breathes (with the animal type of respiration)—but it has neither lungs nor gills; the whole body takes in oxygen and gives off carbonic acid. It swims about—yet it has neither legs nor fins; the pulpy mass of its body flows, when it is necessary, into a crown of streamers or loose processes, that keep the body neatly balanced; when they are no longer required, they sink back into the gelatinous mass. We study the “histology” of these curious social-living creatures under a powerful microscope. As I have explained, the tissues and organs of the higher animals break up under the microscope into a most ingeniously constructed network of tiny living gelatinous