452 



BIOLOGY OF THE PROTOZOA 



7 nuclei 1 of which is cast out as a "reduction" nucleus; 2 are 

 involved in the formation of the two valves of the spore and ulti- 

 mately disappear; 2 are connected with the elaboration of the polar 

 capsules and similarly disappear and 2 remain as germinal nuclei. 

 It is generally assumed that these 2 nuclei are descendants of the 





Fig. 189. — Leptotheca ncissura, vegetative individuals with well-developed spherules. 



(After Davis.) 



original dimorphic nuclei of the trophozoite and observations by 

 Schroder (1910), Davis (1916), Erdmann (1911 and 1917), leave 

 little doubt that they ultimately fuse in autogamous fertilization 

 p. 547). 



The spores which differ from sporoblasts of the Telosporidia in 



