What is Paramecium?
Paramecium is a protozoan and belongs to a group called Infusoria, all members of which possess cilia either all of their lives or at least part of their lives. (Cilia are the "hairs," by which these animals move about.)
The paramecium is white in appearance and can be collected from submerged pond weeds. It is sometimes called the "slipper animalcule", since the front end of the animal is more rounded than the back end. The widest part is behind the center of the body.
The entire animal is covered with cilia bent backward, forcing the paramecium through the water in a spiral path, and to the left, most of the time.
You will notice, in the illustration, that a depression extends from the front end and to one side. This is called the oral groove.
Bacteria and protozoa are captured by the paramecium with the aid of cilia in the oral groove. The food and some water continue down the groove through the cell mouth into a short tube, the gullet, and eventually into the cell where it is held until digested.
Waste products are excreted through the "skin" of the paramecium.
Near the mouth opening can be seen both a small nucleus and a large nucleus, appearing as darker masses within the cell.
Reproduction in the paramecium can be a simple process of splitting in two, through the center of the animal's body. Each daughter paramecium has, as a result of the division, both nuclei and an oral groove, and are completely identical.