258 ILLINOIS BIOLOGICAL MONOGRAPHS [496 



EXPLANATION OF PLATE 



Figs. 602 to 621. Mitraspora elongata. Original. X1500, except Figs. 620 and 621, X2500. 

 Giemsa staining, unless otherwise stated. ft. 



Fig. 602. A trophozoite showing various nuclei and sporoblasts at different stages of devel- 

 opment. 



Fig. 603. A trophozoite with a mature and a young spore. Iron hematoxylin. 



Fig. 604. A trophozoite with two mature spores. 



Figs. 605 to 609. Formation and development of sporoblasts. 



Figs. 610 to 613. Developing spores. Fig. 612; Delafield's hematoxylin. 



Fig. 614. A surface view of a preserved spore. 



Fig. 615. An optical section of a preserved spore. 



Fig. 616. Front view of a stained spore. 



Fig. 617. Lateral view of a spore stained with Heidenhain's iron hematoxylin. 



Fig. 618. A slightly elongated spore. 



Fig. 619. An abnormal spore. 



Fig. 620. A longitudinal section thru a polar capsule. 



Fig. 621. An oblique view of a polar capsule, showing the spirally coiled polar filament. 



Figs. 622 to 627. Myxidium americanum. Original. X1500. 



Figs. 622 and 623. Two young trophozoites. Giemsa. 



Fig. 624. A sporulating trophozoite in unstained preserved state. 



Fig. 625. A spore in preserved state. 



Fig. 626. A fresh spore treated with potassium hydrate solution. 



Fig. 627. A spore stained with Giemsa's mixture. 



Figs. 628 to 631. Myxobolus mesenlericus. Original. X1500. 



Figs. 628 and 629. Front and lateral views of unstained preserved spores. 



Fig. 630. A Giemsa stained spore. 



Fig. 631. A spore with extruded polar filament (potassium hydrate), stained with Giemsa's 

 mixture. 



