Ch. Ill, 10] PLANTS WITHOUT CHLOROPHYLL 



85 



the minute reproductive spores in the air where the winds 

 can scatter them. Indeed, were it not for the sporophore, 

 often the presence of the hidden mycelium would never be 

 suspected. The familiar 

 mushrooms and molds 

 have this structure. 



Parasites, whether flow- 

 ering plants or fungi, enter 

 and penetrate their hosts 

 by use of digestive fer- 

 ments, or enzymes, put 

 forth by the tips of the 

 entering haustoria. En- 

 zymes are definite chemi- 

 cal substances which have 

 power to digest (i.e. con- 

 vert into soluble forms) 

 the cell walls, starches, 

 and proteins; and these 

 digested materials are 

 absorbed into the roots 

 or mycelium and form 

 food for the parasite. It 

 is precisely the same with 

 saprophytes. The damage 

 done by parasites to their 



hosts is of three sorts, — Fig. 60. — The Indian Pipe, or Ghost 



first, the removal of food, ? lant « **• » !* as no chlorophyll but 



mm is translucent white in color. (From 



thus tending to starve the Bailey.) 



host plant; second, the 



excretion of injurious or poisonous substances apparently 



by-products of the parasite's own metabolism; and third, 



the disturbance of the growth-control mechanism, resulting 



in the production of various monstrosities. 



Parasites and saprophytes are relatively small plants, the 

 majority being microscopic; and they constitute an insig- 



