346 



äfven utan blötning i vatten tillräckligt fuktig och klibbig för att 

 kunna liksom fastlimma sporerna vid de fasta föremål, hvarmed de 

 komma i beröring. 



FEOM WHERE ORIGINATES THE BROWN POWDEK ON THE SURFACE 

 OF POLYPORUS APPLANATUS, POL. LUCIDUS ETC? 



Summary. 



The opinion or theory set forth by Schulzer in Flora, 1878: 11, 

 and Oesterr. bot. Zeitschrift, 1880: 321, and endorsed by several 

 other mycologists, viz. that the powder often occurring on the sur- 

 face of Hymenomycetes, for instance the chocolate-brown powder 

 on Polgporus applanatus, Pol. lucidus etc, consists of conidia which 

 originate on the surface where they lie, is not to be upheld, be- 

 cause it seems to be incompatible with the following facts: 



1. Said powder is not restricted to the fungus surface itself, it 

 occurs also on leaves, bark-pieces, sand-grains and other objects 

 accidentally adhering to said surface. 



2. It occurs not only on the fresh and living surface but 

 also on laccate and resinous surfaces and even on old and dead 

 ones which can not be consid^red adapted to generate spores or 

 conidia. 



3. Some pieces of card-board pinned on the surface of Polypo- 

 riis applanatus in May proved in July to be covered with a layer 

 of the brown powder, and so was the surface of the fungus also 

 except the spöts, which had been protected by the card-board pie- 

 ces. Moreover the upper surface of the leaves of a small plant of 

 Acer overshadowing the fungus also proved to be covered with the 

 brown powder, though these leaves were situated 10 — 20 cm. above 

 the fungus, and no fungus was growing above. 



These facts show that the powder must have been suspended in 

 the air before it accumulated. And the uniformity of the layer 

 suggests the opinion that it was deposited in calm weather. This 

 being admitted, we are obliged to believe that the powder origina- 

 tes from the pores and thus consists of basidio-spores. 



But how can the spores be lifted and suspended in the air, 

 though they are heavier than the air and thus should fall instead 

 of rise? 



