It is rather remarkable that the Theory of the Permanence of Continents and Oceans has passed so comparatively unchallenged by geologists. I long since attempted to show that Mr. Wallace's supposition that the Chalk was a shallow and littoral sea deposit was untenable. In comparing analyses of chalk, as he does, with Atlantic ooze, no allowance whatever is made for the loss of iron from the body of the chalk by crystallization, nor for the segregation of silica into flints. The Chalk may have undergone so great a change in addition, since its upheaval vast ages ago, through the removal of some of its constituents by percolating water, that comparative analyses can only be of value when these losses are taken into consideration.