SECTION IY. 



THE FLAGELLATA OR MONADS. 



THK Flagellata or Monads are exceedingly minute 

 protozoa, having oval bodies, with a nucleus and a con- 

 tractile vesicle, and one or two long whip-like cilia. It is 

 on account of the last-named fact that they have been 



called Flagellata. 



FIG. 743. 



Monads (UreJIa), magnified 1,000 diameter*. From Am. Naturalist. 



Not far removed from the Monads even if they do 



not belong with them are the 

 Noctilucse (Fig. 744), very minute 

 organisms which abound on the 

 surface of the sea, and which are 

 remarkable for their phosphores- 

 cence. They have a somewhat 

 spherical and jelly-like body, with 

 a groove on one side, from which 

 there extends a thread-like loco- 

 motive organ. 



FIG. 744. 



Noctiluca miliaris Magnified. 



