DESCRIPTION OF PLATES 



Unless otherwise stated, all figures are made from camera drawings or sketches 

 from the living cells. 



The figures in plates 1 and 2 are of Spathidium spathula, those in plates 3 and 

 4 of Actinobolus radians. 



PLATE 1 



EXPLANATION OF FIGURES 



1 Freehand sketch of Spathidium showing nucleus, contractile vacuole, 

 mouth, lines of insertion of the cilia and oral cilia. 



2 Optical section of total preparation to show cuticle, cortex, endoplasm 

 and chromatin granules in the nucleus. X 400. 



3 Sketch of total mount showing trichocysts in rim of the mouth. X 400. 



4 and 5 Sketches of total preparations to show variations in form of the 

 nucleus. X 400. 



6, 7 and 8 Freehand sketches of abnormal forms found a short time before 

 the death of the series. 



9 Total preparation showing the nucleus divided into two distinct parts 

 each of which is tightly coiled. X 400. 



10 Longitudinal section showing fragments of "the macronucleus and an 

 elongated vesicular body containing deeply staining bodies in process of division. 

 X 415. 



11 A retort-shaped body found in section i-epresented in fig. 14. X 1673. 



12 Anterior region of body showing trichocysts, drawn from total prepara- 

 tions. 



13 Sketch of mouth region drawn from living form. 



14 Longitudinal section showing nucleus, food particles and retort-shaped 

 body shown in figure 11. X 415. 



15 Sketch showing relation of the elongated and retort-shaped bodies found 

 in the serial sections pictured in figure 10 and 14. X 1673. 



16 Total preparation illustrating another variation in the form of the nu- 

 cleus. X 415. 



17 Sketch of mouth region from living animal. 



18 Section showing cortical foldings in the gullet. X 415. 



19 and 20 Sketches of early division stage to show elongated chromatin 

 granules. X 415. 



21 and 22 Sketches of a late division stage showing the fine chromatin gran- 

 ules. X 415. 



400 



