At a recent meeting of the Boston Natural History Society, as reported in the Traveler, Professor Agassiz, gave an account of his recent visit to the reefs of Florida, and explanations of coraline growths. He estimates the rate of coral growth to be only a few inches in a century, a tenth or a twelfth part less than has been hitherto supposed ; and, supposing the reef rises from a depth of twelve fathoms, he would calculate its age upon its arrival at the surface of the water to be about twenty-five thousand years, and the total age of the four distinct concentric reefs of the southern extremity of the peninsula to be one hundred thousand years. Professor William B. Rogers said that the physical conditions could not have differed much in that region a hundred thousand years ago from what they now are, and consequently that such a calculation could reasonably be made upon the data accumulated by Professor Agassiz. Dr. D. F. Weinland annihilated such speculations by stating that, while in Hayti, he had noticed branches of some kinds of corals from three to five inches above the water, which must have grown that much during the short winter of three months, when the water was high. His observations went to prove that some kinds of corals were more rapid in their growth than is generally believed to be the case.