254 



GENERAL MORPHOLOGY OF PLANTS 



separated before the formation of the germ sporangium, so that 

 the spores in one germ sporangium from a single zygospore are 

 all + while in another they are all . 



The Water Molds. 



410. The water mold. These fungi grow on dead insects or 

 other animals in the water, or even on dead plant parts. They are 

 very common on dead insects, and sometimes are seen growing on 



Fig. 213. 



Sporangia of Saprolegnia, one with zoospores escaping and passing through the first 

 swarming period. Below, passing through second swarming period and then germinating. 



living but weakened fish and other aquatic animals. They are 

 easily obtained by collecting algae with some of the ditch or pond 

 water in which they grow, and throwing dead flies into it. The 

 mycelium grows through the body of the fly, and then long white 

 threads radiate out in the water all around the insect. The myce- 

 lium is coarsely granular, vacuolate, and continuous. 



