74 



Plant Life and Evolution 



more or less branched tubular filaments have no 

 division walls, and, except for the absence of chloro- 

 phyll, resemble very closely a common green alga, 

 Vaucheria. As in the latter, there are two sorts of 



FIG. 6 



A Sexual reproductive organs of a siphoneous alga, Vau- 

 cheria, compared with those of a water-mold, Rhiphidium, B. 

 C Zoosporangium of Vaucheria. 

 D Zoosporangium of a water-mold, Saprolegnia. 

 B After Thaxter. 



reproductive organs, non-sexual zoospores, and sex- 

 ually produced resting spores. 



Eumycetes or True Fungi. The 40,000 or more 

 species known as true fungi, or Eumycetes, present 

 an almost hopeless tangle of forms which is just be- 

 ginning to be unraveled. At present the classifica- 



