DEVELOPMENT OF SPERMATOBIUM. 29 



EXPLANATION OF THE FIGURES. 

 Plate I. 



Spermatobium Freundi figures: 1 to 4, 6 to 9, 11 to 18, 20 to 32, 34 to 37, 

 39 to 41, 43 to 45. 



Spermatobium Eclipidrili figures: 5, 10, 19, 35, 38, 42. 

 All the figures are drawn from parafine sections stained with Orange G. 

 and Ehrlich H^emotoxylon. All di'awings were made under Zeiss Obj. 1-12 

 horn. imm. Oc. 2. Some of the detail figures were drawn on a larger scale, 

 but not under a higher power. 



Fig. 1a. a spermatogonium of the host containing a parasite in very 

 early stage of development. 

 n. h. nucleus of host. 

 p. protozoa parasite. 

 Fig. 1b. Another spermatogonium from the same. The Spermatobium is 

 more advanced in development, having nearly occupied the 

 whole cell, the nucleus of which is yet intact. 

 n. h. nucleus of the host, 

 c. h. cytotheca of the host. 

 11. sp. nucleus of Spermatobium. 

 V. c. vacuole in the cytoplasm of the parasite. 

 Fig. 2a. a free Spermatobium. The nucleus is globular, the nucleolus is 

 also globular and well defined. At the apex of the cytotheca 

 are seen the commencement of vacuoles c. s. b. 

 Another nearly adult Spermatobium. 

 An adult Si^ermatobium, with commencing vacuoles. 

 Nucleus 'of the same. 



Another Spermatobium of more regular form. 

 The nucleolus of the latter drawn on a larger scale in order to 

 show the intranucleolar bodies. 

 11. nucleus. 

 no. nucleolus. 

 no. b. intranucleolar bodies. 

 Fig. 5. An adult Spermatobiiim from Eclipidrilus. 

 cys. cytospheres. 

 n. nucleus. 

 no. nucleolus. 

 Fig. 6. Surface view of a Spermatobium Freundi, showing the cyto- 

 spheres and their relative size compared to those of Spermato- 

 bium eclipidrili. 

 Fig. 7a. An adult Spermatobium, with nucleus in a stage of budding. 

 Fig. 7b. The nucleus and nucleolus of the latter. 



Fig. 8a. An adult Spermatobium, with a nucleus yet more advanced in 

 budding, nodes and micronuclei already having formed in places. 



Fig. 



2b. 



Fig. 



3a. 



Fig. 



3b. 



Fig. 



4. 



Fig. 



4b. 



