It has been shown that there were more coniferous genera to be found in Europe during the Tertiary than there are at the present-day. Some of the genera now occur only in America and the Far East. Many such genera were present in the Neogene of Europe and one of these, Tsuga, remained in Europe into the Late Pleistocene. Other genera found in Europe at the present-day had, in a number of cases at least, somewhat of a different distribution than now. In the present undertaking much use is made of results derived from pollen studies and it is suggested that pollen may be one of the major lines of evidence leading to a solution of certain phytogeographical problems.