Let us take a brief glance at the various specializations and trade developments, which have taken place in the different groups of cells, and see to what extent the profound modifications which many of them have undergone are consistent with their individuality and independence, and also whether such specialization can be paralleled by actually separate and independent organisms existing in animal communities outside of the body. First of all, because furthest from the type and degraded to the lowest level, we find the great masses of tissue welded together by lime-salts, which form the foundation masses, leverage-bars, and protection plates for the higher tissues of the body. Here the cells, in consideration of food, warmth, and protection guaranteed to themselves and their heirs for ever by the body-state, have, as it were, deliberately surrendered their rights of volition, of movement, and higher liberties generally, and transformed themselves into masses of inorganic material by soaking every thread of their tissues in lime-salts and burying themselves in a marble tomb. Like Esau, they have sold their birthright for a mess of "potash," or rather lime; and if such a class or caste could be invented in the external industrial community, the labor problem and the ever-occurring puzzle of the unemployed would be much simplified. And yet, petrified and mummified as they have become, they are still emphatically alive, and upon the preservation of a fair degree of vigor in them depends entirely the strength and resisting power of the mass in which they are embedded, and of which they form scarcely a third. Destroy the vitality of its cells, and the rock-like bone will waste away before the attack of the body-fluids like soft sandstone under the elements. Shatter it, or twist it out of place, and it will promptly repair itself, and to a remarkable degree resume its original directions and proportions. So little is this form of change inconsistent with the preservation of individualism, that we actually find outside of the body an exactly similar process, occurring in individual and independent animals, in the familiar drama of coral-building. The coral polyp saturates itself with the lime-salts of the sea-water, much as the bone-corpuscles with those of the blood and lymph, and thus protects itself in life and becomes the flying buttress of a continent in death. In the familiar connective-tissue, or "binding-stuff," we find a process similar in kind but differing in the degree, so to speak, of its degradation.