130 



Man's attitude towards the unknown — his philosophy in short 

 — must influence his attitude towards botany as it will towards 

 any science ; and since philosophy, like other lines of intellectual 

 activity, changes and progresses, man's attitude towards science 

 is not a fixed or rigid one. But it is not likely that philosophy 

 will ever tend to discourage investigation, and investigation is 

 the keynote of scientific progress. Unquestionably, the world 

 demands research, and any fact no matter how humble, if accu- 

 rately established, helps on the cause. Perhaps the time will 

 come when our knowledge of to-day will seem as crude as that 

 of yesterday now seems to us. Let not that concern us, except 

 to urge us to do what we may in hastening this time, knowing 

 that that is where real progress lies, and knowing too that there 

 is ample work that can and must be done. 



A KEY TO THE WHITE AND BRIGHT-COLORED 

 SESSILE POLYPOREAE OF TEm'pERATE 

 NORTH AMERICA— III* 



By William A. Murrill 

 K. The Species of Coriolus 



1. Tubes more or less entire, at least until the sporophore is quite old. 2 

 Tubes soon breaking up into long irpiciform teeth, 19 



2. Surface of pileus wholly or partly glabrous when mature or clothed only with 



inconspicuous hairs. 3 



Surface of pileus clothed entirely with a conspicuous, hairy covering. 17 



3. Pileus not entirely glabrous at maturity. 4 

 Pileus entirely glabrous at maturity. 13 



4. Pileus marked at maturity with glabrous zones of a different color from the 



rest of the surface. 5 



Pileus not marked with glabrous zones, but nearly uniform in color and rarely 



shining. 'o 



5. Glabrous zones large, numerous, conspicuously and variously colored. 



C. versicolor (L. ) Qu61. 

 Glabrous zones small and comparatively inconspicuous. 6 



6. Surface villose between the zones, which are late in appearing ; plants small, 



1-2 cm. in diameter. C. hirsuttilus (Schw. ) Murrill 



* This concludes the series of keys to the pileate species of polypores found in 

 temperate North America. The resupinate species are more difficult, most of them 

 requiring the facilities of a well-equipped herbarium, as well as considerable experi- 

 ence, for their proper determination. 



