VOLUME XLVI : NUMBER 5 
BOTANICAL GAZETTE 
NOVEMBER 1908 
OBSERVATIONS ON POLYPORUS LUCIDUS LEYS. AND 
SOME OF ITS ALLIES FROM EUROPE AND 
NORTH AMERICA? 
GEORGE F. ATKINSON 
(WITH FIVE FIGURES AND PLATE XIX) 
The close relationship between the fungus flora of Europe and 
North America has long been recognized. There are many species 
which are common to both countries. This in a large measure is due 
to the same general conditions which have long been recognized in 
explaining the similarity between the spermatophytic floras of the 
two countries, namely, the strong evidence presented by certain 
geologic periods that many centuries ago the two floras were con- 
tiguous in the arctic regions, at a time when the climate there was 
mild enough to permit the growth of those species and genera, con- 
tributing through their progeny the present representatives, which 
have survived the climatic and edaphic rigors to which they were 
subjected during the subsequent glaciation of the arctics, and the 
shifting glacial movement farther to the south, The fungus flora 
of a Country bears a very close and important ecological relation to 
other plants, especially to the spermatophytic flora, whether as para- 
Sitic, humus-dwelling, or wood-destroying species. They are ‘camp 
followers” of the higher plants. Because of this symbiotic and meta- 
biotic relation of the fungi to other plants, in a great measure their 
Sdging and migration is coincident with that of their hosts. In the 
“ase of the forest fungi there are some interesting examples of tena- 
Clous adherence to specific hosts, or to descendant species which 
have become separated in the migratory movement from the parent 
* Contribution from the Department of Botany, Cornell University, No. 130. 
321 
