Spore Surface of a Polyporus 



Here is a very ordinary • looking specimen 

 growing beside the stone steps at our back door 

 perhaps. Its top is gray; its gills beneath are fawn- 

 color. We may shake it as rudely as we will, and 

 yet we shall get no response such as the puff-ball 

 will give us. But let us lay it upon a piece of 

 white paper, gills downward, on the mantel, and 

 cover it with a tumbler or finger-bowl, so as to ab- 

 solutely exclude the least admission of air. At 

 the expiration of five minutes, perhaps, we may 

 detect a filmy, pinkish-yellow tint on the paper, 

 following beneath the upraised border of the cap, 

 like a shadow faintly lined with white. In a 



Spore Surface of an Agaricini 



