150 MICROSCOPY FOR BEGINNERS. 



which makes it look almost hunch -backed. Under a 

 high power it shows two flagella, one of them throwing 

 itself into a coil or loop when the Infusorium settles 

 down to rest, which, by -the -way, it quite frequently 

 does. The body is filled with small colorless disks 

 which the iodine solution turns blue, showing that they 

 are starchy. 



Fig. 119. Chil<S- Fig. 120. Phicns Fig. 121. Phdcns 



monas. pleuronctes. longicuudns. 



13. PHACUS (Figs. 120, 121). 



The body of Phdcus is flattened, thin, and rather like 

 a small leaf. It is widest in front, usually rounded, and 

 tapering from the centre to the short, pointed, colorless 

 tail-like prolongation ; at the broad end it has one long 

 flagellum, often difficult to see. There are several spe- 

 cies in our ponds, all of which are green. 



1. Body not twisted at the rear, tail short, curved. Ph. 



pleuronectes, Fig. 120. 



2. Body twisted or not at the rear, tail long, straight. 



Ph. lonfficaudus, Fig. 121. 



14. UVELLA (Fig. 122). 



The little animals forming these rapidly swimming 

 and revolving colonies are united by their narrow ends 

 into almost spherical microscopic masses, varying in 



