Still less explicable in any way thus far proposed are certain remedial actions seen in animals. An example of them was furnished in § 67, where "false joints" were described--joints formed at places where the ends of a broken bone, failing to unite, remain moveable one upon the other. According to the character of the habitual motions there results a rudely formed hinge-joint or a ball-and-socket joint, either having the various constituent parts--periosteum, fibrous tissue, capsule, ligaments. Now Mr. Darwin's hypothesis, contemplating only normal structures, fails to account for this formation of an abnormal structure. Neither can we ascribe this local development to determinants: there were no appropriate ones in the germ-plasm, since no such structure was provided for. Nor does the hypothesis of physiological units, as presented in preceding chapters, yield an interpretation. These could have no other tendency than to restore the normal form of the limb, and might be expected to oppose the genesis of these new parts.
Thus we have to seek, if not another hypothesis, then some such qualification of an existing hypothesis as will harmonize it with various exceptional phenomena.
§ 97d. In Part II of the _Principles of Sociology_, published in 1876, will be found elaborated in detail that analogy between individual organization and social organization which was briefly sketched out in an essay on "The Social Organism" published in 1860. In §§ 241-3 a parallel is drawn between the developments of the sustaining systems of the two; and it is pointed out how, in the one case as in the other, the components--here organic units and there citizens--have their activities and arrangements mainly settled by local conditions. One leading example is that the parts constituting the alimentary canal, while jointly fitted to the nature of the food, are severally adapted to the successive stages at which the food arrives in its progress; and that in an analogous way the industries carried on by peoples forming different parts of a society, are primarily determined by the natures of things around--agriculture, pastoral and arable, special manufactures and minings, ship-building and fishing: the respective groups falling into fit combinations and becoming partially modified to suit their work. The implication is that while the organization of a society as a whole depends on the characters of its units, in such way that by some types of men despotisms are always evolved while by other types there are evolved forms of government partially free--forms which repeat themselves in colonies--there is, on the other hand, in every case a local power of developing appropriate structures. And it might have been pointed out that similarly in types of creatures not showing much consolidation, as the _Annelida_, many of the component divisions, largely independent in their vitalities, are but little affected in their structures by the entire aggregate.