STRUCTURE, ETC., OF PLEISTOPHORA PERIPLANETH. 633 
Fig. 43.—Vacuole occupying nearly the whole of the length of the spore. 
Nucleus situated at one end. 
Fig. 44.—Nucleus divided into two. 
Figs. 45, 46, and 47.—Showing change in position of two daughter 
nuclei from end of spore to its middle. The vacuole has increased in 
its refractive power. Fig. 47 represents the latest stage of the spore to 
stain satisfactorily. The two nuclei show indications of division. 
Fie. 48.—Spore in about the same condition as in Fig. 47, seen from the 
side. 
Fic. 49.—Ripe spore showing the suture between the two halves of the 
shell or spore coat. 
For Figs. 50 and 51 see Plate 37. 
