20 



Invertebrata. 



as a prospective meal they converge around it, and 

 touching each other coalesce, and draw the particle 

 within the body proper, in which it is digested. As 

 these creatures are homogeneous or nearly so, any 

 one spot is as suitable for the protrusion of pseudo- 

 podia or for the taking in of food as another, but 



FIG. 8. 



Rotalia Veneta, a Rhi/opod, showing the pseudopodia. 



usually the processes are most numerous opposite the 

 holes in the shell. 



As the protoplasm includes its food in the manner 

 described, foreign particles and fine granules become 

 enclosed in it derived from the undigested parts of the 

 food. Sometimes drops of water or of thin fluid may 

 be seen in the protoplasm like little bubbles ; these 

 are called vacuoles (fig, 14), and they with the gran- 



