PROTOZOA OR SIMPLEST ANIMALS. 



15 



Flagellata. 



The Flagellata are Corticata in whicli the cell-body is provided High Wall 

 with one or a few flagella. The cell may be solitary (Fig. 11a), or ^^^ , . 

 may be joined with others to form colonies (Figs. 11b, c). Gallery. 



Fig. 11. 



Flagellata. a. Cercomonas crassicauda, a oue-celled Flagellate. (x 400). 

 B. Gnnium pectorale (x 325). c. Volvox qlohator with daughter and grand- 

 daughter colonies (X 55). (After Carter.) d. Surface view of Volvox 

 showing cells in hexagonal spaces in common jelly ; n, nucleus ; cv, con- 

 tractile vacuole. Very highly magnified. (After Biitschli.) e. Vertical 

 section of wall of Volvox (x 800). a, pairs of flagella. (After Colin.) 



Volvox globator (Figs, llo, i), e), and Plate IXa. in the Case, occurs 

 at times in great abundance in ponds, even to the extent of giving a 

 green colour to the water. The little organism, which is about gL of 

 an inch in diameter, looks like a tiny green speck moving about in 



