WHAT IS EOZOON? 63 



addition multitudes of microscopic pores tlirougli wliicli 

 tlie soft gelatinous matter can ooze^ and form outside 

 finger-like or thread-like extensionsfor collecting food. 

 In some cases tke sliell consists of a single cavity only, 

 but in mostj after one cell is completed^ others are added, 

 forming a series of cells or chambers communicating 

 with each other, and often arranged spirally or other- 

 wise in most beautiful and symmetrical forms. Some 

 of these creatures, usually named Foraminifera, are 



Fig. 17. Polymorphina. 



A many-chambered Poraminifer. Magnified as an opaque object. Figs. 14 to 

 17 are from original sketches of Post-pUocene specimens. 



locomotive, others sessile and attached. Most of them 

 are microscopic, but some grow by multiplication of 

 chambers till they are a quarter of an inch or more in 

 breadth. (Figs. 14 to 17.) 



The original skeleton or primary cell- wall of most of 

 these creatures is seen under the microscope to be per- 

 forated with innumerable pores, and is extremely thin. 

 When, however, owing to the increased size of the 

 shell, or other wants of the creature, it is necessary to 



