actual appeal to arms, leading probably to conflict and bloodshed; it must be admitted that the society, regarded as a whole, has so been rendered more heterogeneous. Or when a dearth causes commercial panic with its entailed bankruptcies, closed factories, discharged operatives, political agitations, food riots, incendiarisms; it is manifest that as, throughout the rest of society, there still exists the ordinary organization displaying the usual phenomena, these new phenomena must be regarded as adding to the complexity previously existing. Nevertheless, it is clear that such changes so far from constituting a further stage of evolution, are steps towards dissolution. There is good reason to think then, that the definition arrived at in the last chapter, is an imperfect one. We may suspect, not that the process of evolution is different from the process there described; but that the description did not contain all that it should. The changes above instanced as coming within the formula as it now stands, are so obviously different from the rest, that the inclusion of them implies some oversight—some distinction hitherto overlooked. Such further distinction we shall find really exists. * * * * * § 54. At the same time that all evolution is a change from the homogeneous to the heterogeneous, it is also a change from the indefinite to the definite. As well as an advance from simplicity to complexity, there is an advance from confusion to order—from undetermined arrangement to determined arrangement. In the process of development, no matter what sphere it is displayed in, there is not only a gradual multiplication of unlike parts; but there is a gradual increase in the distinctness with which these parts are marked off from each other. And so is that increase of heterogeneity which characterizes Evolution, distinguished from that increase of heterogeneity which does not. For proof of this, it needs only to reconsider the instances given above. The structural changes constituting a disease, have no such definiteness, either in locality, extent, or outline, as the structural changes constituting development. Though certain morbid growths arise much more commonly in some parts of the body than in others (as warts on the hands, cancer on the breasts, tubercle in the lungs), yet they are not confined to these parts; nor, when found on them, are they anything like so precise in their relative positions as are the normal parts around them. In size, again, they are extremely variable—they bear no such constant proportion to the body as organs do. Their forms, too, are far less specific than organic forms. And they are extremely irregular or confused in their internal structures. That is to say, they are in all respects comparatively indefinite. The like peculiarity may be traced in decomposition. That state of total indefiniteness to which a