EXPLANATION OF PLATE 

 PLATE 37 



All figures of P eniatriclwmonas ardin delieili (Derrieu and Eeynaud) X 2500. 

 Material fixed in hot Schaudinn's fluid and stained in iron haematoxylin. Draw- 

 ings made with Abbe camera lueida. 



Fig. 1. Individual with undulating membrane in lateral position, cy-tostome 

 below with chromatin diffused throughout the nucleus. Note detached position 

 of the anterior independent flagellum. 



Fig. 2. ' Ventral ' view with eytostome uppermost and undulating membrane 

 below. Note curvature of axostyle, centrosome on the nuclear membrane, and 

 two karyosomes, probably preparatory to rriitosis. 



Fig. 3. Lateral view with very large nucleus, large karyosome, and food 

 vacuole with contents. 



Fig. 4. Lateral view with remnants of food particles in the eytostome and 

 chromatin encrusted nuclear membrane. 



Fig. 5. Individual which had recently ingested a red blood corpuscle. From 

 life. 



Fig. 6. Lateral view of contracted specimen with much cur\-ed axostyle, and 

 diffusely stained nucleus. 



Fig. 7. Lateral view with protuberant eytostome. Note centrosome on the 

 anterior face of the nuclear membrane, two karyosomes in the nucleus, and the 

 straight axostyle. 



Figs. 8, 9, and 10. Binary fission with two nuclei and a common eytostome, 

 each with its independent neuromotor system. 



[390] 



