HISTOLOGY AND DEVELOPMENT OF MYRIOTHELA PHEYGIA. 537 



Fig. 13. — A Myriotbela bearing buds in various stages. 



Fig. 14. — Section tbrougb ciliated cell zone of the endoderm. 



Fig. 15. — Goblet-cell. Osmic vapour. 



Fig. 16. — Villus of goblet-cell zone. 



Fig. 17. — Two apical cells. 



Fig. 18. — Loaded gland-cell and empty vacuolate cell. 



Fig. 18 «. — Discharged gland-cell. 



Fig. ISb, — Intermediate condition of gland-cells. 



Fig. 19. — Group of small cells from apex of villus. 



Fig. 20. — Oral end of Myriotbela with lip retracted. 



Fig. 21. — Villus from middle region of the body, with gland-cells just com- 

 mencing to discharge. 



Fig. 22. — Group of cells from the endoderm of a blastostyle. Osmic acid. 



Fig. 23. — Villus from the spadix of a gonophore, showing canal-like 

 vacuoles in the lower portion of the cells. At a and a' these are cut across. 



Fig. 24. — Two cells from the endoderm of a blastostyle. Osmic acid. 



Fig. 25. — Nutritive spheres containing pigment granules. Osmic acid, 

 ■j^g^th ob. 



Fig. 26. — Body from the endoderm of a tentacle. 



Fig. 27. — Endoderm-cell containing the large type of nutritive sphere. 



Fig. 28. — Large nutritive sphere. 



