144 CONJUGATION, MATURATION, AND FERTILIZATION 



characterized as follows: Two are destined to degenerate as "reduc- 

 tion nuclei," four become the centres of shell formation of the spores, 

 four become centres of pole capsule formation, and four remain as 



Fig. 00 



Autogamy in Ameba jn-oteu.s. In upper ligure secondary (gametic) nuclei are shown 

 emerging from the primary nuclei. In central figure is pictured the union of gametic nuclei 

 togetlier with some unde\'eloped ones in a |u-imar.y nucleus. In lower figure is sliown the 

 mass of siiorofilasts wliich de\'elt.)it from tlie fertilized gametes, (.\fter Calkins.) 



