PALYNOLOGY AND PLEISTOCENE ECOLOGY 369 



without encountering a single specimen. If, however, the apocrats with 

 regard to their pollen grains behave like Trifolium pratense, for instance, 

 there will be only a shght chance, if any, of finding their pollen in surface 

 samples. 



From the study of surface samples — unfortunately much neglected hither- 

 to — it is evident that pollen statistics affords a means of tracing the history 

 of at least some apocrats and thus, at the same time, of the ecological condi- 

 tions of which they are characteristic. 



Fossil apocrat pollen grains. Hippophae pollen has already been dealt with. 

 Another interesting pollen type, at least in part apocratic, is Artemisia. These 

 pollen grains were identified after having been referred to for many years 

 as ""Salix 2" by early pollen analysts, even though they realized that the 

 pollen grains were not produced by species belonging to that genus. 



Hippophae and at least some of the Late Glacial Artemisia are examples of 

 ananthropochorous apocrats whose appearance and dispersal have not been 

 influenced by man. The history of anthropochorous apocrats as well as other 

 plants, the distribution of which was disturbed by deforestation through 

 clearing and cultivation, has been dealt with in great detail by Iversen in his 

 important "landnam" paper (Iversen, 1941). Special attention should be 

 paid to Centaurea cyanus, generally believed to be a typical anthropochorous 

 element that attained its present distribution in Europe in connection with the 

 cultivation of rye. After a report — in 1948— on findings of pollen grains of 

 Centaurea cyanus in Late Glacial deposits, several stray finds of this charac- 

 teristic pollen type have been made in various countries. Of particular interest 

 is the report by Schmitz (1957) on pollen grains of Centaurea cyanus in a bog 

 in northern Germany, from Late Glacial deposits right up to recent layers. 



The finds were made not far from Kiel. In the neighborhood there is a place 

 called Schwedeneck where the steep slopes of the Baltic end moraine are 

 continuously being eroded and broken down by the sea. In the loose slopes 

 grow the moss Dicranella varia and many other plants of a more or less 

 decidedly apocratic habit. A narrow path borders the upper margin of the 

 slope a foot or two from the declivity. Between this path and the slope is a 

 characteristic assemblage of plants, including, i.a., Artemisia and Centaurea. 

 There they are secure: nobody, neither man nor beast, walks along the 

 edge of an abyss. Theoretically this assemblage could be a rehct of Late 

 Glacial vegetation that has maintained itself through all the vicissitudes of 

 cUmate and vegetational change in Post-glacial times. Our scanty knowledge 

 of the history of these plants seems to be due to the fact that their pollen 

 grains cannot be expected to have been accumulated in appreciable numbers 

 in bogs and other polliniferous deposits because such are rare in the vicinity. 



A sort of parallel to the conditions at Schwedeneck is found at Mount 

 Omberg in southern Sweden. Here it may be possible, as pointed out, e.g. 

 by Hedberg (1949), that some plants now growing on or near the mountain 



