FERTILIZATION BY EXOGAMY 



159 



but not as complete as in the gregarines; one case, Adelea ovafa, is 

 interesting in that one of the conjugants is a large form similar to the 

 ordinary vey;etative individuals, while the other is much smaller and 

 is derived from an individual which forms four gametes while attached 

 to the other cell, one of these gametes penetrating the larger cell, while 

 the other three degenerate and disappear. In this form also we have 



Fig. 69 







-.^ 



i;-2>-^ 



; 



Different forms of gametes in gregarines and t-occidiidia. (After Slieliack.) ^1, Styin- 

 rliynchus longicollis faftcr Lf'ger); li, a species of monocystis from Lumbricus (Cueiiot); C, 

 spermatozoid of Mcliiiiomera hispida, to the left tiie two gametes of Pterocepliahis nobilis; 

 D. the two gametes of l'rosi)ora lagidis (Hrasil); E, the same of Cregarina ovata (after 

 Sciinitzler); F, the same of Scliaudiniiella heiilex' (after Nusbaiini); (J, the same of Cocci- 

 (lium schubergi (after Schaudinn). 



what may he regarded as (■<)nij)lete sex (Hll'erentiation, since the ])roto- 

 plasin of (he race forms indivithials of male or female character, never 

 i)()(h. Schaudinn and others have shown that the difference between 

 the two conjugating forms is present in ])()tential tin-ongliout the 

 entire series of forms, the first division of the fertilized egg giving rise 

 to individuals which can he identified as male or female. In tins case^ 



