“Yes, my boy,” answered the engineer, “and that gives me a new argument in support of my theory. It is certain after what we have seen that the animals in the island are numerous, and what is more curious, is that the species are extremely varied. There must be a reason for this, and mine is, that Lincoln Island was formerly a part of some vast continent, which has, little by little, sunk beneath the surface of the Pacific.” “Then,” said Pencroff, who did not seem entirely convinced, “what remains of this old continent may disappear in its turn and leave nothing between America and Asia.” “Yes,” said Smith, “there will be new continents which millions upon millions of animalculæ are building at this moment.” “And who are these masons?” inquired Pencroff. “The coral insects,” answered Smith. “It is these who have built by their constant labor the Island of Clermont Tonnerre, the Atolls and many other coral islands which abound in the Pacific. It takes 47,000,000 of these insects to deposit one particle; and yet with the marine salt which they absorb, and the solid elements of the water which they assimilate, these animalculæ produce limestone, and limestone forms those enormous submarine structures whose hardness and solidity is equal to that of granite. Formerly, during the first epochs of creation, Nature employed heat to produce land by upheaval, but now she lets these microscopic insects replace this agent, whose dynamic power at the interior of this globe has evidently diminished. This fact is sufficiently proved by the great number of volcanoes actually extinct on the surface of the earth. I verily believe that century after century, and infusoria after infusoria will change the Pacific some day into a vast continent, which new generations will, in their turn, inhabit and civilize.” “It will take a long time,” said Pencroff. “Nature has time on her side,” replied the engineer. “But what is the good of new continents?” asked Herbert. “It seems to me that the present extent of habitable countries is enough for mankind. Now Nature does nothing in vain.” “Nothing in vain, indeed,” replied the engineer; “but let us see how we can explain the necessity of new continents in the future, and precisely in these tropical regions occupied by these coral islands. Here is an explanation, which seems to me at least plausible.” “We are listening, Mr. Smith,” replied Herbert.