Total insubordination among the centres of development, is shown where the units or cells, as fast as they are severally formed, part company and lead independent lives. This, in the vegetal kingdom, habitually occurs among the _Protophyta_, and in the animal kingdom, among the _Protozoa_. Partial insubordination is seen in those somewhat advanced organisms, that consist of units which, though they have not separated, have so little mutual dependence that the aggregate they form is irregular. Among plants, the Thallophytes very generally exemplify this mode of development. Lichens, spreading with flat or corrugated edges in this or that direction as the conditions determine, have no manifest co-ordination of parts. In the _Algæ_ the Nostocs and various other forms similarly show us an unsymmetrical structure. Of _Fungi_ we may say that creeping kinds display no further dependence of one part on another than is implied by their cohesion. And even in such better-organized plants as the _Marchantia_, the general arrangement shows no reference to a directive centre. Among animals many of the Sponges in their adult forms may be cited as devoid of that co-ordination implied by symmetry: the units composing them, though they have some subordination to local centres, have no subordination to a general centre. To distinguish that kind of development in which the whole product of a germ coheres in one mass, from that kind of development in which it does not, Professor Huxley has introduced the words "_continuous_" and "_discontinuous_;" and these seem the best fitted for the purpose. Multicentral development, then, is divisible into continuous and discontinuous. From central development we pass insensibly to that higher kind of development for which _axial_ seems the most appropriate name. A tendency towards this is vaguely manifested almost everywhere. The great majority even of _Protophyta_ and _Protozoa_ have different longitudinal and transverse dimensions--have an obscure if not a distinct axial structure. The originally spheroidal and polyhedral units out of which higher organisms are mainly built, usually pass into shapes that are subordinated to lines rather than to points. And in the higher organisms, considered as wholes, an arrangement of parts in relation to an axis is distinct and nearly universal. We see it in the superior orders of Thallophytes; and in all the cormophytic plants. With few exceptions the _Coelenterata_ clearly exhibit it; it is traceable, though less conspicuously, throughout the _Mollusca_; and the _Annelida_, _Arthropoda_, and _Vertebrata_ uniformly show it with perfect definiteness.