498 



LIFE-HISTORIES 



Fig. 327. — Water-mold {Saprolegnia Thureti, Water-mold Family, 

 Saprolegniacew) . A, dead fly attacked by water-mold, surrounded 

 by radiating hyphse terminating in swarm-spore-eases, }. B, swarm- 

 spore-case in which the spores are forming, 2?e. C, same, discharging 

 swarm-spores. E, female gamatangium containing four female gametes 

 to which comes a projection from the male gametangium that arises 

 as a branch hypha from below the female gametangium, *','"■ (Thuret, 

 DeB.ary.) — Water-molds abound upon dead insects, etc., in water. 



a convex partition, swells into a sporangium which becomes 

 filled with a number of spores. These are soon scattered, 

 and are then ready to produce new mycelia in the manner 

 already described. Such non-sexual spores, serving as do 

 swarm-spores for rapid multiplication, float like dust in the 

 air, and may thus be distinguished as dust-spores. 



Comparatively large aiul resistant zygospores are formed by the 

 conjugation of special branches as shown in Fig. 32G. The zygospore 



