"In its most primitive form, life is, therefore, no longer bound to the cell, the cell which possesses structure and which can be compared to a complex wheel-work, such as a watch which ceases to exist if it is stamped down in a mortar. No, in its primitive form life is like fire, like a flame borne by the living substance;-like a flame which appears in endless diversity and yet has specificity within it;-which can adopt the form of the organic world, of the lank grass-leaf and of the stem of the tree."