144 Aquatic Organisms 



eggs of fishes during their incubation (see fig; oo on 

 p. go). 



Most water molds Hve upon other plants. Even the 

 Saprolegnias have their own lesser mold parasites: 

 Many living algae, even the lesser forms like desmidg 

 and diatoms are subject to their attack. Fine cultures 

 of such algas are sometimes run through with an 

 epidemic of mould parasites and ruined. 



