INDIVIDUALITY AIL. indiridualitas, from indiridualis, relating to an individual). Separate er distinct existence. There is some difference of opinion as to what, constitutes indi viduality, the discussion being principally con fined to the domain of natural history. Some authorities regard the various organising spring ing by buds from a single hydroid as indi vidual. Others consider various parts of a tree to be individuals. In one sense all the organisms proceeding from one egg may he eonsidAred ac constituting one individual. since they are de rived from one germ. and the production of the zordds by budding is similar to the development of a stock by grafting: but similar only beemise, inn grafting a part of one individual, and not a germinal part, is inserted into another. and there proceeds to grow, as if the original plant ex tended itself. But in the budding of hydroids the different zordds produced exactly resemble each other, depart from each other, and develop independently into hydroids like their parent ; and some may develop much more rapidly than others. The production of a zooid is more like original germination or ovum development than the growth and extension of a part of the com mon tissues of a parent.
Individuality, in the psychological sense, which is different from the preceding biological and physiological meanings of the term, has reference to the personality of experience which is largely constituted by the continuity of the personal memory. Cases have not infrequently been re ported where this memory continuum has been broken off and another instituted in its place, as the result of hypnotism or some form of disease. A person thus affected loses all memory of pre vious bodily existence, together with name, home, family, and friends, and begins a life so entirely new and different that he may be called another and different personality. The greatest number of personalities mutually ignorant of the exist ence of others connected with the same brain is five, in the case of Louis V., reported by 116urru and Burot in Variations de la personnalite (Paris, 1888). For further information, consult: Binet, Alterations de la personnalite (Paris, 1892) ; Janet, L'automatisme psychologique (Paris, 1889) ; James. Principles of Psychology (New York, 1890) ; Podmore, Studies in Psychi cal Research (London, 1899). See DOUBLE CON SCIOUSNESS.