264 EVENINGS AT THE MICROSCOPE 



atoms are thus arrested by these cilia, and are hurled by 

 their vibrations down this gulf. Yet not all, nor nearly 

 all; for the lips appear to possess the sense of taste, OP 

 of some modification of touch, which enables them to re- 

 fuse or receive the atoms presented to them, so that only 

 such particles pass down the throat as are selected for 

 food. Some of the atoms of pigment are admitted, and 

 one of the most pleasing sights connected with these ani- 

 mals is to watch the swallowing of colored food, its re- 

 ception into the singular sunken mouth, where the great 

 powerful jaws act upon it: thence its dismissal through 

 the gullet, where certain glands pour upon it their secre- 

 tions, into the stomach, where other glands, answering to 

 a liver, change it, and thence into the intestine and rec- 

 tum, until its indigestible portion is discharged through 

 the cloacal orifice. 



The object of the mingling of color with the water ia 

 which these and similar animals are held for observation 

 was the tracing of the phenomena of digestion. And, 

 indeed, it renders the whole process beautifully distinct; 

 for, from the transparency of the tissues, the presence of 

 the colored pellet is everywhere recognizable, since it re- 

 tains its form and hue under all its changes, clearly re- 

 vealing to us the shape, dimensions, and directions of the 

 various canals through which it passes; here and there 

 diffusing throughout the viscus in which it is held a 

 beautiful roseate hue, more or less deep, without, how- 

 ever, losing its own definite outline. 



Let me now direct your attention to the organs de- 

 voted to the seizing and mastication of the food. And 

 the more because the form of these organs in the Hotifera 

 is quite peculiar quite unlike what is found in any other 



