J02 PKYIUM\ PROTOZOA THE SIMPLEST ANIMALS 



Eighth Type of Protozoa GREGARINA 



Gregarina, a type of Sporozoa in which the cell is divided 

 into two regions by a partition. 



Description. Various species occur in the intestine of 

 the lobster, cockroach, and other Arthropods. When young 

 they are intracellular parasites, but later they become free in 

 the gut. They feed by absorbing diffusible foodstuffs, such 



FlG. 45. Life history of Greganna. After Biitschli. 



x. Young forms (a, b, c) emerging from intestinal cells (z'.c.)] **.. 

 nucleus of intestinal cell. 



2. Two forms conjugating (G. blattaruin). 



3. Spore formation within a cyst. 



4. Adult with decid upus head-cap (c.c.), and a cuticular partition 



dividing the cell into an anterior part (A) and a posterior part 

 () ; ., the nucleus. 



5. A spore within its spore-case (sp.c.). 



as peptones and carbohydrates, from their hosts, and store 

 up glycogen within themselves. In many the size is about 

 one-tenth of an inch. There is a firm cuticle of "proto- 

 elastin," which grows inwards so as to divide the cell into 

 a larger nucleated posterior region and a smaller anterior 

 region, and also, in the young stage, forms a small anterior 

 cap. The cell substance is divided into a firmer cortical 

 layer and a more fluid central substance. The protoplasm 

 often presents a delicate fibrillar appearance, suggesting 

 that of striated muscle. The nucleus is very distinct, but 

 there are no vacuoles. We may associate the absence of 



