110 THE AMERICAN MONTHLY [April 



This remarkable form was found very abundant and 

 was given prolonged study. In the active flagellate 

 stage it moved about in an easy manner, revolving on its 

 long axis; the fiagellum being thrown iuto graceful 

 curves from its origin to its distal end. After moving 

 about for an hour, more or less, the coming change to the 

 heliozoan stage was ushered in by a slower movement, 

 an occassional halt, slight tremors and the appearance 

 on the anterior body half of short, heavy and blunt ten- 

 tacle-like processes, with a simultaneous contraction of 

 the body. 



If the endoplasm was well filled with the granules men- 

 tioned, the body would be modulated. The rays then 

 extended until as long as one or two of its diameters; 

 the tentacle-like processes covering the anterior half, 

 going to form the anterior rays; the fiagellum becomes 

 inactive and is coiled close to the body. In this state it 

 resembled very much a light colored Heterophry Leidy, 

 changing its contour gradually and almost impercept- 

 ably, but never to any great extent. 



The change from the heliozoan to the flagellate stage 

 is heralded by the gradual withdrawal of the rays, the 

 fiagellum uncoiling and having a slight movement, a few 

 slight quivers of the body and simultaneous elongation 

 to the original shape of the flagellate; the flagellum be- 

 comes very active at once and the infusorian darts off to 

 live for an hour or so in this phase. Sometimes the 

 original form is not restored entirely until it has moved 

 about for a sihort while, but in all cases observed the 

 original shape was finally assumed. 



Each one of the phases of tliis dual life, as witnessed 

 by the writer occupied from fifteen minutes to one and a 

 half hours. 



While in the heliozoan stage the manner of capturing 

 and engulphing food is identically the same as when per- 

 formed by th^ Actinophry sol. One form tliat was ui\- 



