FIG. 60. Phytophthora infestans, a fungus whose asexual reproductive 

 bodies are usually motile zoospores. The sexual mode of reproduction 

 has disappeared. In allied species the conidia do not contain zoospores, 

 but produce a germ-tube on germination. This sometimes happens with 

 P. infestans, which thus illustrates a fungus occupying a transitional stage 

 between the older aquatic types which constantly produces zoospores, and 

 the more modern types, where the conidia are dispersed by wind, and on 

 germination produce a germ-tube. 



