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What is Copromonas and where is it found ? 



One of the Flagellates. It differs from Euglena in shape, 

 in the attachment of the flagellum, and chromatophores 

 are absent. It is a parasite in the intestine of the Frog 

 and the Toad. 



Write an Account of Volvox. 



Pond water in summer often contains revolving green 

 spheres each about as big as the head of a small pin ; thesn 

 are the colonies of Volvox. The Volvox colony (a hollow 

 sphere) is an aggregate of perhaps 10,000 biflagellate indi- 

 viduals closely connected together. Each cell body does 

 not fill its capsule, there is a gelatinous matrix between ; 

 and the capsule is hexagonal, since each cell is pressed 

 close against six surrounding cells. Further, each cell 

 body is connected to the six adjoining ones by six delicate 

 strands which pass through its capsule wall. 



The colony is physiologically an individual organism, 

 exhibiting unified locomotor activities of its constituent 

 units. It also shows structural differentiation ; for while 

 most of its units are nutritive or somatic, a few are special- 

 ised for reproduction. Each of these units or cells has a 

 nucleus, a contractile vacuole, a chromatophore, a pyrenoid 

 with paramylum granules, and two flagella. Projecting 

 from the colony surface, the flagella by combined action 

 propel the colony which rolls forward, sometimes to the 

 right, more often to the left. 



The reproductive cells are larger than the others and have 

 no flagella ; and they are called parthenogonidia. By 

 repeated binary fission each gives rise to a new spherical 

 colony. These, at first small, pass into the cavity of the 

 mother colony, and are set free by rupture of the mother 

 colony. This asexual method is continued for several 

 generations, and then colonies appear which have a num- 

 ber of cells like parthenogonidia ; but they (gametocytes) 

 behave differently. Some (macrogametocytes) grow large 

 and pass into the cavity ; these are female cells or macro- 

 gametes. Others (microgametocytes) by repeated division 



