without allowing any objection: the aim of life is life's continuation. CHAPTER III SCALE OF SEXES Asexual reproduction.--Formation of the animal colony. --Limits of asexual reproduction.--Coupling.--Birth of the sexes.--Hermaphrodism and parthenogenesis.--Chemical fecundation.--Universality of parthenogenesis. The primitive mode of reproduction is asexual, or what one will so consider provisorily, in comparison with more complex mechanism. In the first living forms there are neither sexual organs nor differentiated sexual elements. The animal reproduces itself by scissiparity or by budding; the individual divides itself in two parts, or a protuberance develops, forms a new being and then separates. Scissiparity is an inexact term, for the division is transversal, and the two parts far from equal; it occurs in protozoaires, and further in worms, star-fish and polyps. Budding is common to protozoaires, infusoria, cœlenterata, to fresh-water polyps and to nearly all vegetables. A third primitive mode, sporulation, consists in the production inside the organism of particular cells, spores, which separate and become individuals; this occurs in protozoaires, as well as in ferns, algæ and mushrooms. The first two modes, division and budding, serve also for the formation of animal colonies, when the new individual retains a point of contact with the generating individual. It is by this notion of colony that one explains complex beings, and even superior animals, in considering them as reunions of simple primitive beings which have differentiated themselves and still retained a solidarity, sharing the physiological work between them. Colonies of protozoaires are formed of individuals having identical functions, living in perfect equality, despite the hierarchy of position; colonies of metazoaires are composed of specialised members whose separation may be a cause of death for the total individual. There is then, in the latter case, a new being composed of distinct elements which, retaining a certain essential autonomy, have become the organs of a new entity.