458 C. CLIFFORD DOP.ELL. 



To the left of the nucleus is seen the cystostonie. Numerous food particles 

 are seen in the posterior part of the body. This figure is drawn on a larger 

 scale than the others. 



rigs, 2 — 10 show division as observed in the living animal. (Por the 

 sake of clearness, the nucleus is represented as being more distinctly 

 outlined than is really the case.) 



Fig. 2. — Animal before division. 



Fig. 3.— Animal becoming rounded posteriorly. Axial rod disappearing. 



Fig. 4. — Nucleus has become dumb-bell sliaped, and there are now two 

 bunches of rapidly vibrating flagella, at the base of which a refringcnt spot is 

 visible, no longer attached to nucleus. 



Fig. 5. — Flagella separating — likewise the nuclei. These latter are still 

 connected by a protoplasmic strand, however. 



Fig. 6. — Body has become elongated, and a constriction has appeared. 

 Nuclei still connected, and flagella now distinctly seen to consist of two 

 groups of four each, one being in each case directed away from the other 

 three. 



Fig. 7. — Separation of daughler-cells from one another. Nuclei still con- 

 nected, and lying between the two individuals. 



Fig. 8. — Daughter-individuals nearly drawn apart. 



Fig. 9. — One of the daughter-individuals soon after separation. Tiie 

 nucleus, which lay at the extreme posterior end, is now making its way ante- 

 riorly, and the axial rod is seen behind it. 



Fig. 10. — Later stage of same individual. The nucleus has not yet reached 

 the base of the flagella, and the growth of the axial rod is therefore not yet 

 complete. 



Fig. 11. — Preparation, showing nucleus, basal granule, and flagella, etc. 



Fig. 12. — Stage in division, corresponding with F'ig. 4. The chromatin 

 masses at the bases of the groups of flagella are well shown. 



Fig. 13. — Specimen at about the stage seen in Fig. 10. 



Fig, 14. — Large individual dividing into three. Living animal. 



Fig. 15. — Degenerate animal which has become aniccboid. The nucleus is 

 breaking up, and there are, in addition, many food particles in the cytoplasm. 



The specimens reproduced in Figs. 11, 12, 13, and 15 were stained by 

 Giemsa's method. 



