THE PROTOZOANS 



453 



Chap. 21 



Like ciliates, suctorians have two types of nuclei, larger and smaller and of 

 different function. The animals conjugate and all the embryos are ciliated. 



Fig. 21.20. Suctorians. Podophyra fi.xa, com- 

 mon protozoans of fresh water. The tubular ten- 

 tacles are attached to a ciliate and the suctorian 

 sucks in the substance of its prey. (Courtesy, Jahn 

 and Jahn: The Protozoa. Dubuque, Iowa, Wm. C. 

 Brown and Co., 1949.) 



Sucking tentacles 

 in use 



Such similarities make it seem probable that suctorians were originally ciliates, 

 now greatly changed in structure and habits. 



