68 PRINCIPLES OF ANIMAL BIOLOGY 



stalks and all, in a mass of jelly. Such colonies may be as large as 

 walnuts, or even baseballs. 



A third type of colony is the gregaloid, in which the cells are irregularly 

 placed in a mass of jelly. These cells may be loosely arranged and in 



Fig. 50. Fig. 51. 



Fig. 50. — A gregaloid colony, Proterospongia haeckeli. {From Hegner's "College 

 Zoology," The Macmillan Company.) 



Fig. 51. — Pandorina morum, a spheroid colony. 



contact with one another by means of fine processes branching out from 

 them (Fig. 49), or they may be quite separate with only the jelly to hold 

 them together (Fig. 50). 



Somewhat more compact and more regularly arranged are the spheroid 

 colonies. In these there is usually a mass of jelly nearly spherical in 



A B 



Fig. 52. Fig. 5:3. 



Fig. 52. — A spheroid colony, Eudorini elegans. A, adult colony, X475; B, daugh- 

 ter colony, X7.30. {From West after Goehd.) 



Fig. 53. — Anthophysa vegetans. Spheroid colonies arranged on a branching stalk, 

 thus combining two typos of colonies. {After Kent.) 



shape, in which cells are imbedded in a layer near the surface, but none 

 is in the center. The cells may be actuall\' in contact, or nearly so 

 (Fig. 51), especially in young colonies (Fig. 52/i), or widely separated, 

 as in most such forms when older (Fig. 52A). 



