EXPLANATION OF THE FIGURES. 



PLATE XVI. 



Phytophthora infestans. 



Fig. i. Back of potato leaflet attacked by the fungus showing the characteristic 



dark spots with pale mouldy margins. 

 ., 2. Conidiophores bearing conidia emerging from a stoma on the underside 



of a leaflet. Highly magnified. 

 3. Conidium with protoplasm dividend into blocks, the latter being liberated 



as zoospores in Fig. (4). 



5. Zoospore coming to rest and losing its cilia. 

 6. A zoospore which has germinated. 



7. A conidium which has germinated directly and sent out a germ-tube. 

 Figs- (3), (4), (5), (6) and (7) very highly magnified. 



