182 



SEX IN MICROORGANISMS 



Fig. Q. 



Life-cycle stages of various Radiolaria: 1-5 from Brandt (1885); 6-17 from Brandt 

 (1905)', 18-23 from Kuhn (1926), after Huth (1913); 24-28 from Schewiakoff (1926), 

 all redrawn. 1, developing microspores (left) and macrospores (right) in Sphae- 

 rozoum punctatum; 2, 3, isospores of Collozomn fulvuni; 4, 5, macrospore and 

 microspore of Collozown ineniie (2-5 from living material); 6, 7, macrospores, 8, 

 9, microspores of Sphaerozoum punctatum (from living material); 10-23, Thalas- 

 sicolla nucleatnm: 10, 11, macrospores; 12, 13, microspores; 14, 15, isospores killed 

 with iodine; 16, 17, from living material; 18-20, early to late stages in Schlauchkern- 

 serie, 21, higher magnification showing mitoses in stage shown in 20, note increase 

 in size with growth of Scblmicl^kernserie; 22, microspore from Schlauchkernserie; 

 23, macrospore from Spindelkernserie; 24, "gamete" of Fhyllostaurus cuspidatus; 25, 

 "gamete" of Fleuraspis costatus; 26, "gamete," 27, 28, "zygotes" of Acanthostaums 

 pnrpurasceiis. 



