54 



Some Acinetarians have a stalk or peduncle. Their way 

 of feeding is remarkable. They have no mouths ; they 

 fasten on to their prey or food by the suckers and by means 

 of these extract the nutrient substance. Many of them 

 are parasitic. Reproduction is by fission and gemmation 

 (budding). Acineta, a well-known freshwater and marine 

 genus, is found attached to Hydroids. 



11. Acineta. (Magnified.) 



CLASS SPOROZOA (GREGARINES). 



Indicate the Characteristic Features of the Sporozoa and 

 their Importance. 



They are parasitic Protozoa which infest the tissues and 

 internal organs of almost ail animals, from worms up ta 

 and including Man. Many are minute in size, some are 

 as long as half an inch. Being internal parasites, and 

 feeding by osmosis, simply absorbing through their cuticle 

 the juices of their hosts, they have no special structures 

 for ingesting and digesting food. There are no food vacuoles 

 and no contractile vacuoles ; only a nucleus is present in 

 the body. The body has finely granular endoplasm (the 

 medulla) with a thin border of ectoplasm (the cortex) 

 which contains contractile fibrillse. Movement is amo3- 

 boid or euglenoid, and the shape of the body alters little. 



