30 



PEOTOZOA. 



connecting substance in which the cells are imbedded appears to be 

 quite structureless ; but in some specimens delicate, branching, minutely 

 granular fibrils may be seen radiating from each cell into the connecting 

 substance (fig. 14, 4). 



Fig. 14. 



Structure of ThalassicoUa (after Professor Huxley). 



In the second form of ThalassicoUa , the creature consists of a sphe- 

 rical mass of jelly, as large as the middle-sized specimens of the last 

 variety, with an irregular blackish central mass. Enveloping this, and 

 forming a zone about half the diameter of the sphere, are seen nume- 

 rous clear spaces (vacuoles), and among these are scattered numerous 

 yellow cells and a multitude of very dark granules. Delicate, flattened, 

 branching fibrils radiate from the innermost layer, passing between the 

 vacuoles ; and in one specimen Professor Huxley observed these fibrils 

 thickly beset with minute dark molecules which were in active motion, 

 as if circulating along the fibrils, but without any definite direction. 



