CEMAILAR DEGENERATION AND FORMATION OF PJUMEN'J'. 123 



(text-fig. 9, a-g). In this condition no nucleus can be 

 detected. 



These curious bodies are transformed cells or portions of 

 cells. In text-fig. 9, a and b, early stages in the formation of 

 the bodies can be seen. The whole cell tends to become 

 pear-shaped, or a pear-shaped area becomes differentiated 

 around the nucleus. In this area relatively large (0"8 ju), 

 rounded, pale brown globules are gradually formed (text- 

 fig. 9, c). The globules increase in number (fig. d) and the 

 nucleus becomes clear and does not stain readily. Sometimes, 



Text-fig. 8. 



Sertularia linealis Warreu. x 2000. 



as in fig. E, the nucleus may remain in a comparatively 

 unaltered condition in a portion of the undifferentiated cyto- 

 plasm of the cell. The globules gradually fuse together and 

 become much darker brown. In figs. E and F the fusion of the 

 globules is seen to be taking place, the fusion being less 

 complete on the left side than on the right. In fig. G the 

 fusion is complete and the body consists of a more or less 

 homogeneous substance of a dark brown colour and measures 

 about 11 ^ X 4 ^. 



There is naturally considerable variation in the size and 

 shape of the brown bodies, but there is a very obvious distinct 

 tendency for them to possess a pear-shaped outline both in 

 the ectoderm and endoderm. The bodies in the endoderm are 

 often more elongated and larger than those in the ectoderm, 

 but the difference between them is not as considerable as 

 would be expected from the difference in the character of the 



