272 THE RING OF NATURE 



that grow on tree trunks, and end by turning into 

 wood as hard as that of the host, cankers. The 

 likeness of this word to our most dread disease 

 has led even some responsible scientists to suggest 

 that cancer may grow first on decaying trees and 

 then infect the human body. Certainly, fungi 

 (assuming for a moment that cancer is one) are 

 most resourceful colonizers. Many are known 

 to live at will on hosts of totally different kind, 

 such as the wheat smut on the barberry, while 

 waiting for a crop of wheat to devastate. No 

 doubt there .are very many others with the same 

 habit not yet discovered. A wounded larch, 

 the only one in the county, is almost certain to 

 attract the peziza that is the larch's especial pest. 

 It comes from the air, say the wise men, thinking 

 that because it is unseen it must be a case of 

 spontaneous generation. So they said of plague 

 and smallpox not many years ago, but we know 

 better to-day. 



Conceivably, the larch may escape the peziza, 

 but never will the apple escape the fungus that 

 turns its juice into cider, or the barley grain its 

 own ferment, or the bit of bread thrown out its 

 semblance of blood, or the plate of jam its crop 

 of white whiskers. The spores must have been 

 waiting somewhere for the opportunity of getting 

 each one its respective food. 



A little is known of the life history of some of 

 the worst of the minute fungi. Ergot of rye, that 

 now and then infects whole races of those who 



