92 PLANT-ANIMALS [CH. 



end, whilst, in others, a single, large drop lies close 

 against the anterior margin of the cell, separated 

 from the tissues of the animal only by the thinnest 

 of membranes. Finally, other large globules may 

 be seen lying just outside the colourless borders of 

 yellow-brown cells and presenting the appearance 

 of having been extruded from them. We conclude 

 that the fat-globules, formed in the yellow-brown 

 cells of C. paradoxa, pass by a process of secretion 

 from these cells to those of the animal and serve the 

 animal for nutritive purposes. 



It is very probable that a similar secretion occurs 

 in C. roscofiensis. For, in the first place, starch, 

 which, as we have learned, appears in the green 

 cells as the result of photosynthesis, does not occur 

 in the other tissues of C. roscoffensis. In the second 

 place, this animal does not possess the power of 

 digesting starch. When supplied with starch grains, 

 it ingests them readily, transfers them to the 

 vacuoles which lie in its digestive tract, but is 

 unable to dissolve them. They remain for a time 

 in the . vacuoles, and are then discharged by a 

 temporary rupture of the surface of the body. 

 In the third place, in carefully prepared and 

 stained sections through the body of C. roscoflensis, 

 there may be seen rows of fatty granules passing 

 from the green cells to the neighbouring animal 

 cells (Fig. 17, F.G.). Nor does a conversion of 



