138 



into several smaller spores, called zoospores, so ex- 

 tremely minute that when 3,000 are laid side by side 

 in a line they only reach an inch. 



The zoospores soon emerge from the spore, and each 

 one of these becomes quickly furnished with two 



Pig. 17 The stages of germination of one of the conidia of Phytophthora. 

 (a) the ripe conidium in water ; (6) protophsmic contents breaking up 

 into blocks, which separate and escape (c and d) as minute kidney- 

 shaped zoospores (e), each with two cilia ;/and.i r , the zoospore coming 

 to rest and losing its cilia ; h, i, /and /, successive stages of germina- 

 tion of the zoospore. Highly magnified. Marshall Ward. 



extremely fine hair-like cilia, tails or vibrating hairs. 

 The zoospores are able to move in the slightest film of 

 moisture, being propelled by the whipping motion of 

 the cilia. After a brief time the little zoospores, or 

 animal-like spores, rest, and take a globular form, and 

 the vibrating hairs dissolve away, or drop into the 



