As always in the classification forms which have the characteristics of two major groups and which the microbiologist must classify arbitrarily. The importance of the protozoa lies in the fact that their major source of food are microscopic plants. The rotifers are more complex animals than protozoa, being multicellular rather monocellular. Their body is still flexible like the protozoa but one of their characteristics lies in the action of cilia, short, hairlike appendages. The rotifer's cilia are located on its head and serve as its organ of motility, as well as the means ofr obtaining food. these cilia are located in two circular rows and move in a manner that gives the appearance of two counterrotating wheels and hence the name rotifer. 생물학 전공 서적인가봐 영어 잘하는 횽들 좀 부탁할께 ㅠ_ㅠ