68 ALBUGO PORTULAC& OR A. CANDIDA. 



and with best results in a film of water, such as is formed 

 by heavy dew. To promote distribution still further, 

 each conidium often breaks up into several active zo- 

 ospores, which, after moving about for fifteen minutes 

 or so, finally come to rest, put out a mycelial tube that 

 penetrates the host, and form a new plant. The zo- 

 o spores, except in being colorless like the parent, remind 

 one of those of Ulothrix, serving the same purposes of 

 distribution and reproduction. 



The absence of septa, except for the separation of 

 the antheridia, oogonia, and conidiospores, making the 

 vegetative portion a continuous cavity, is a character 

 shared with Cladophora, Vaucheria, and Mucor, as well 

 as many other forms, both green and non-green. 



