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Uiiiversitij of California PuhUcations in Zoology [Vol. 16 



in the structure of their parabasal bodies as well as in the behavior of 

 these organelles in division. These forms are Trypanoplasina and 

 Polymastix bufonis (Dobell). 



In Trypanoplasma an increase in the complexity of the motor ap- 

 paratus is shown in the attachment of the trailing flagellum to the 

 body by a membrane, which is more or less well developed (fig. 34). 



Figs. 4.3-50. Pohjmastix bufonis (Dobell), X 2066. Fig. 4.3. Trophozoite; 

 end view showing horseshoe-shaped parabasal body. Fig. 44. Normal active 

 trophozoite showing the parabasal body with some evidences of organization. 

 Fig. 45. Early projjhase of division. Fig. 46. The same stage. Fig. 47. Or- 

 dinary trophozoite. Fig. 48. Prophase of division. Fig. 49. Late prophase. 

 Fig. 50. Late anaphase. 



The parabasal body presents many aspects in different species. In T. 

 carassii sp. nov. (fig. 10) it is a rounded, compact body, connected 

 with the nucleus on one side by a rhizoplast and on the other with the 

 blepharoplast. In T. congri (Martin, 1913, fig. 35) it is stretched 

 out lengthwise of the cell, sometimes lobed or constricted. Gelei (1913) 

 shows how widely this structure may vary in T. dendrocoeU, in form 

 as well as in its staining reactions, in the same species. At the time of 

 division it elongates and becomes separated in the middle by a simple 



