INFUSORIA. 141 



objects, is divided at the summit into many branches, 

 with one Infusorium at the end of each, and many oth- 

 ers scattered along them with shorter branches of their 

 own. Through the main stem and through all the 

 branches there extends a cord-like muscular thread that 

 suddenly contracts when the animals are frightened or 

 disturbed, and pulls the whole colony down towards the 

 point of attachment to the plant. But the branches 

 may contract one at a 

 time and draw their bur- 

 den of Infusorial fruit 

 down to the main stem 

 without disturbing any 

 other portion of the col- 

 ony, or all the branches 

 may contract at once. 



Therefore, while the ani- F , g toT ._ Carch6gium . 



mals on the branches are 



connected together, they are still somewhat independ- 

 ent. The front border of each body is surrounded by 

 a circle of cilia visible under a high power. They 

 are the only cilia on the body. When the animal is 

 contracted they are folded together, each body then 

 resembling a little ball. They vibrate rapidly, produc- 

 ing circular currents that bring to the mouth any food- 

 particles that may be in the vicinity. The entire col- 

 ony is colorless, and may include as many as a hundred 

 Infusoria on the branches. It can be seen by a low- 

 power objective. The independent contraction of the 



