SOIL PROTOZOA. 331 



Figs. 5-8. Earl3' stajres in nuclear division. 



9-12. Four small chromosomes present in the nucleus. 

 13-16. Fragmentation of chromosomes and division of the nucleus. 

 17-20. Eionsration and division of kinetonucleus and constriction of the hody 

 into two daughter-organisms. The new trophonuclei are unrecognisable 

 in these stages. 

 Fig. 21. Two daughter-organisms neai-ly separated ; new trophonuclei visil)le. 

 22. Small recently separated daughter-form. 



Plate II. 



Owing to the exigencies of space in raaking up the Plate, the full extent of 

 the two pairs of llagella is shown only in tigs. 23 & 26. 



Tetramitus spiralis, sp. n. All figures X 2786. 



Figs. 23 & 24. Two normal forms, showing the groove. 



25 & 26. Showing the relations of flagella, hlepharoplasts, rliizoplasts, and 

 nucleus. 

 Fig. 27. Showing new flagella arising from anteriorlj- enlarged hlepharoplasts. 



28. The flagella have migrated before the nucleus shows signs of division. 

 Figs. 29-33. Successive stages in early phases of nuclear division. 



31-30. Stages showing four principal chromatin masses within the dividing 



nucleus. 

 37-41. Later stages in nuclear division. 



PlATE III. 



Figs. 42-45. Tetramitus spiralis, sp. n. X 2786. 



Figs. 42-44. Later stages of division, showing the formation of daughter-organisms. 



in tig. 43 there appears to be a production of large vacuoles on the 



longitudinal axis of the bodj'. 

 Fig. 45. The two new organisms have just separated. 



Figs. 46-48. Spironema nnilticiliatum. X 1833. 



Fig. 46. A rather small form having 8 flagella and showing the contractile vacuole 

 at the beginning of the tail. The extra-karyosomic part of the 

 nucleus has ^ery small granules on its outer edge. 



47. A lunger form showing 18 flagella, rather irregularly disposed. 



48. A long_ form showing spiral twist of the anterior part of the body and 



contractile vacuole towards posterior end. 



Figs. 49-55. Amoel/a lawesiana, sp. n. X 1833. 



Fig. 49. Normal individual of typical Umax form, showing feebl}' staining granules 

 just iiisiile the imclear membrane, and a mass of adherent bacteria' 

 at posterior end. 



Figs. 53-52. Early stages in nuclear division showing disintegration of the karyosome 

 and the production of a chain of chromatin granules or chromosomes. 



Fig. 53. The formation of the spindle at rirst, having broad ends extending be- 

 yond the nuck'ar membrane The chromosomes are arranged in an 

 equatorial band. 



Figs. 54 & 55. The spindle has become pointed at each pole and is placed obliquely 

 to the horizontal plane ; ring of chromosomes. 



Plate IV. 

 Figs. 56-65. Amoeha lawesiana. X 1833. 



Fig. 56. Equatorial ring just divided. 



Figs. 57 & 58. Elongation of the spindle and separation of the new chromatin 



bands. 

 Fi"". 59. Late stage of nuclear division, showing a twisting of the central portion 



of the spindle. 

 60. Commencement of constriction of the organism. 



