278 EVENINGS AT THE MICROSCOPE 



erally full of green and brown food, but they will not 

 imbibe carmine. 



Let us look, however, a moment longer at the singular 

 foot. Between the first and second joints there are two 

 projecting spines; these differ much in different individ- 

 uals as to their length, slenderness, and direction; some- 

 times being quite short, at others as long as the toes; 

 generally, they arch downward, but occasionally they 

 stand out straight, or even curve upward. In some speci- 

 mens these spines appear to be processes of the first joint, 

 but in others we can see distinctly that they belong to a 

 little intermediate piece between the first and second ap- 

 parent joints. Between the two toes, on the hinder 

 aspect, projects from the last joint a small spine, which 

 is perhaps the rudiment of a third toe, since we find that 

 number in some genera of this class. The whole foot, 

 including the toes, is rough with the shagreen-like points 

 that cover the lorica. 



You have already noticed the rapidity and fitful irreg- 

 ularity which the long and many-jointed foot confers 

 upon the movements of this curious little form. From 

 the toe-tips, as a point of adhesion, it throws its body 

 to and fro, or from side to side, in a peculiar manner. 

 The toes are sometimes sprawled out, like the legs of an 

 expanded pair of compasses, and sometimes the joints of 

 the foot are suddenly bent in zig-zag fashion, and then 

 as abruptly straightened. The animal swims gracefully, 

 but only with moderate swiftness, the rotatory crown of 

 cilia being small though forming the usual vortices when 

 the animal is moored; while thus swimming, the toes are 

 gracefully stretched behind, nearly in contact with each 

 other. It is lively in its motions, but these seem per- 



