These are very different conditions of existence from those which govern the destinies of the Earth and of the planets of our group. Two suns! What curious alternations of seasons! What variations in the climates! What transformations in the doubtlessly very rapid changes of their vitality! What complications of their calendars, in the succession of their years, their summers and winters, their days and nights! The sole fact of the existence of such a system, relatively near to us and already well-known to terrestrial astronomers, testifies to the infinite variety disseminated in the starry depths of the cosmos. What multiplicity of manifestations of the diverse forces of nature must have been produced in this wealth of solar development--manifestations strange to the phenomena studied on our planet, and which are doubtlessly felt and appreciated by means of senses differing absolutely from those existing in terrestrial organisms, senses awakened, determined, and developed in those distant worlds by their own natural forces. On worlds illuminated, heated, and regulated by two suns life can only have appeared and organised itself in forms very different from those on Earth, having no doubt an alternating double life, served by other modes of perception, other organs, and other senses. The thinker, the astronomer, the physiologist, can no longer regard terrestrial life as the type of all life. All we could learn, study, or know on Earth will never be more than an infinitesimal and absolutely insufficient part of the immense reality embodied in the innumerable creations of the Infinite.