28 FORAMINIFERA. PART in. 



form ; but as the animal grows, others are successively 

 added by a kind of budding in a definite but different 

 arrangement for each order and genus of the class. 

 When the creature increases in size, a portion of its 

 semi-fluid sarcode projects like a bud from the mouth 

 of its shell. If it be of the one-chambered kind, the 

 bud separates from its parent before the shelly matter 

 which it secretes from its surface consolidates, and a 

 new individual is thus produced. But if the primary 



Fig. 97. Various forms of Foraminifora : A, Oolina claxata ; B, Nodosaria rugoaa ; 

 c, Nodosaria spinicosta ; Cristellaria compressa ; K, Polystomella crispa ; F, Den- 

 dritina elegans ; G, Globigerina bulloi'des ; H, Textularia Mayeriana ; I, Quinquelocu- 

 lina Bronniana. 



shell be of the many- chambered kind, the shelly secre- 

 tion consolidates over the sarcode projection which 

 thus remains fixed, and the shell has then two chambers, 

 the aperture in the last being the mouth, from which, 

 by a protrusion of sarcode, a third chamber may be 

 added, the new chamber being always placed upon the 

 mouth of its predecessor, a process which may be 

 continued indefinitely, the mouth of the last segment 

 being the mouth of the whole shell. 



By this process an ovate shell with a mouth at one 

 extremity may have a succession of ovate chambers 



