86 



PRINCIPLES OF ANIMAL BIOLOGY 



tree-like colony. In this species the separation of the cells is complete 

 and the cells rearrange themselves after division. Codosiga (Fig. 54) 



c> 



Fig. 52. — Haplozoon lineare, 

 an example of a linear colony. 

 h, somatic cell; other cells ger- 

 minal. (From Huxley after Dogiel.) 



Fig. 53. — Dinohryon sertularia Eh- 

 ronberg. A, arrangement of cells in a 

 tree-like colony; B, individual in its cup- 

 like sheath. {After Kent.) 



is a stalked form. After a cell divides the two new cells remain attached 

 to the old stalk but each cell begins to secrete a new stalk. With succes- 



FiQ. 54. — Codosiga cymosa Kent. A, treelike form of colony; B, individual cell in detail. 



(After Kent.) 



sive divisions followed each time by stalk-formation a tree-like colony 

 is produced. Anthophysa (Fig. 55) is a further example of a dendritic 



