There are colonies of pelagic tunicates39 which have taken a shape like the finger of a glove. Each member of the colony is an individual animal, but the colony is another individual animal, not at all like the sum of its individuals. Some of the colonists, girdling the open end, have developed the ability, one against the other, of making a pulsing movement very like muscular action. Others of the colonists collect the food and distribute it, and the outside of the glove is hardened and protected against contact. Here are two animals, and yet the same thing—something the early Church would
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