Again, we know by observation and experiment that the function of “life” is to organise matter; that is to say, to arrange material particles into differentiated groups and aggregates marked by varying complexities of composition suitable for certain specific actions. It is sometimes contended that this systematic co-ordination and apparent display of purpose is to be found also in the inanimate world. The phenomenon of crystallisation, for example, is here and there regarded as an instance of life. It is attended by growth. It exhibits both differentiation and integration, becoming on the one hand more complex and on the other more unified. Lost parts are seen to be regenerated. Some degree of adjustment to surroundings is noticeable; and reproduction may even be said to occur to some extent. But when the crystal is formed it does not differ, either in substance or in function, from the raw material out of which it has been constructed. It remains inert and destitute of any approach to vitality. It may be destroyed by crushing, fusion, solution: it never “dies.” To speak of it as being a living creature is, therefore, inept. If, however, great importance be still attached to the occasional regenerations and reproductions observed in the case of inanimate matter, it should be borne in mind that these differ very greatly from the corresponding phenomena where life is concerned. The repairs effected by chemical affinity and other non-vital influences are limited to restoration and replacement without alteration of structure or change of adaptation; and where reproduction takes place it is limited to repetition. Very different results are met with when Life is in control. Take any “horny-handed son of toil.” The skin of his hands when he was a child and until he began to work was soft and tender. It became injured by friction, pressure and the like. It needed repair; and then Life, instead of renewing the softness, gradually developed a condition of toughness and callosity which served as a safeguard against further injury. Such facts as these--and a vast number are known to Science--conclusively establish the essential difference that exists between living matter and matter that is not invested with vitality.