114 



TEE SEA SHORE 



cannot do much better than make an infusion by pouring boiling 

 water on fragments of dried grass, and leaving it exposed for a few 

 days to the warm summer atmosphere. The numerous germs 

 floating in the air will soon give rise to abundance of life, including 



several different species of in- 

 fusoria, varying from -fa to 5^^ 

 of an inch in length. 



Fresh - water pools and 

 marshes provide such an 

 abundance of infusoria that 

 the animals are generally ob- 

 tained for study from these 

 sources, and a few of the 

 common and most interesting 

 FIG. 64. A PHOSPHOEESCENT MARINE s P ecies inhabiting fresh water 

 INFUSORIAN (Noctiluca), MAGNIFIED have already been described in 



a former work. Nevertheless, 



the sea is abundantly supplied with representatives of the class, 

 and it is certain that the beautiful phosphorescence sometimes 

 observed in the sea at night is in part due to the presence of 

 luminous infusoria, some of which appear to have an aversion to 

 sunlight, retiring to a depth during the day, but rising to the 

 surface again after sunset. 



