I.) MICROSCOPIC PLANTS. 23 
pea. There is besides a very large number of these 
small moulds which attack various species of plants 
and fruits. A species of Peronospora (P. effusa) 
attacks spinach; another (P. gaugliformis) is very 
injurious to lettuces; PP. Schleidenitana destroys 
young onions, and PP. ¢rifoliorum attacks the 
lucerne. 
Exigencies of space compel us to close this chapter, 
though the number and variety of microscopic plants 
entitle them to a whole volume; but perhaps suffi- 
cient has been said to show the reader that a large 
amount of recreation and instruction may be obtained 
by a study of these low forms of plant-life. 
