üametogenesis in Cestodes. 
437 
Fig. 1 is from Tliysanosoma actinoides; 4 from Crossobotliriiun laciniatum; 5, 7, 
9 — 11, 20 from Taenia pisiformis; 12 from Moniezia expansa; 13 and 14 from Dipylidium 
caninum; 23 and 24 from Taenia teniaeformis; 3, 15,22 and 25 from either T. Taeniae- 
formis or Dipylidium^); remainder from Rhyncobothrium bulbifer. 
Fig. 1. Uterus, showing embryos (mostly a little out of focus), and certain darkly 
stained structures somewhat simulating polar bodies (especially in lower right liand corner). 
Fig. 2. Ovary showing a bi-nucleate egg at x. 
Fig. 3. Amitosis (at x) in yoimg ovary. 
Fig. 4. Testis showing amitosis at x. 
Fig. 5. Sperms developing in cytophore. 
Fig. 6. Cytopliore containing spermatocyte nuclei in prophase with several sperms 
attached to each of these in several cases. 
Fig. 7. Sperms developing in cytophore, one of them attached to a chromatin 
granule at x. 
Fig. 8. Testes showing spi. Ist spermatocyte and sp^, second spermatocytes in 
cytophores. 
Fig. 9. Skein remnants in cytophore. 
Fig. 10. Testisshowing first and second spermatocytes {sp^,sp 2) andspermatozoa (sp). 
Fig. 11. Part of testis showing first spermatocyte skein (sp^). 
Fig. 12. Young testis showing a fnlly developed nucleus to the right, and the 
chromidial element of a new nucleus at the left^). 
Fig. 13. Young testis showing developing cell containing two minute chromidia at x. 
Fig. 14. Young testis showing daughter cell surrounded by parent cell. 
Fig. 15. Testis showing first spermatocytes (sp^) and cytophore containing skein 
fragments at x. 
Figs. 16, 17, 21, 26, 28, 34 and 35. Cytophores showing more than one sperm 
developing from a single cell area. 
Figs. 18, 19, 27, 37 and 38. Cytophores or parts of cytophores showing sperms 
developing attached to cliromidia in the cytoplasm, or ending freely in the cytoplasm 
itself; but in most cases not attached directly to any nucleus. 
Fig. 2ü. Cytophore showing one sperm to a spermatocyte (spermatid). (Only 
one shown.) 
Fig. 22. Sperm attached to cytophore, showing sperm apparently divided at base. 
Figs. 23 and 24. Early sperm development (23 is earlier than 24). 
Fig. 25. Anucleate fragment of cytophore with attached sperms. 
Fig. 29. Fragment of cytophore with two attached sperms, and containing a 
single nucleus and four chromidia, to one of which a sperm is attached. 
Figs. 30 — 32. Sperms showing slight enlargements (“heads”) at one end. In 
30 the sperm is more nearly matflre than in 31 and 32. 
Fig. 33. Two developing sperms attached to a single nucleus. 
Fig. 36. Cytophore with several developing sperms attached, which were motile. 
Figs. 39 and 41. Nuclei developing from chromidia in early testes. 
Figs. 40, 42 and 43. Cytophores (or parts thereof) showing distributed clrromatin 
fragments, as well as nuclei and attached sperms. 
1) I am uncertain on this point. 
2) From a slide kindly loaned me by Dr. Aute Rich.\rds. 
Archiv f. Zellforschung. XVII. 
29 
