144 Aquatic Organisms 



eggs of fishes during their incubation, as shown in a 

 figure in a later chapter. 



Most water molds live upon other plants. Even the 

 Saprolegnias have their own lesser mold parasites. 

 Many living algas, even the lesser forms like desmids 

 and diatoms are subject to their attack. Fine cultures 

 of such algae are sometimes run through with an 

 epidemic of mould parasites and ruined. 



