Discusses the possibility of a land-bridge connecting Biscay with Ireland and the consequent occurrence in southern Ireland of Asturian plants which are absent from England.

Asks if Hooker or anyone has criticised Edward Forbes’ botanical migration of five floras in the British Isles ["On the connexion between the distribution of existing fauna and flora of the British Isles, and the geological changes which have affected their area", Mem. Geol. Surv. G. B. 1 (1846): 336–432].

CL has calculated that elevation and subsidence of certain formations in Sweden and Norway take place at the rate of 2 1/2 feet per century. He now proposes to estimate the age of a bed by including a conjecture that pauses occur in the oscillations in the ratio of 4 periods of stasis to one of movement. Applying this formula to Scotland, the last subsidence and re-elevation would be 590,000 years and the age of the beds with human implements would be 20,000 years.

Satisfied that CD finds his conjectured rate of elevation and long periods of stasis reasonable, even if these periods cannot be estimated. Explaining upheaval by subterranean lava flow makes these pauses plausible. Suspects that mountainous areas move more than lowland and coastal areas. General upheavals or subsidence in Europe in glacial period are unlikely. Believes with Jamieson that there was glacial action in Scotland before its submergence and that it was equally mountainous then. Subterranean upheaval visits different countries by turn. Horizontal Silurian strata must have been submerged and upheaved. Rest has always been the general surface character. Believes, however, that the quantity of late Tertiary movement is against CD’s belief in the constancy of continents and oceans: perhaps since the Miocene period, but not since the Cretaceous.