Chlorophycae - Volvcales - Eudorina

Phyllum Thallophyta - The Algae - Chlorophycae - Volvcales - Eudorina 
In Eudorina the colony is larger than in Pandorina. I t is oval in shape and consists generally of thirty-two globose cells, loosely arranged on the periphery of a hollow mucilaginous matrix. The biflagellate cells are of the typical chlamydo­monad type, but the chloroplast often has several pyrenoids and the cells show a progressive reduction in the size of the eye-spot as ,ye pass from the anterior to the posterior end of the colony. Unlike Pandorina, the cells forming the colony are connected together by extremely fine protoplasmic strands, only visible after special staining. The flagella are long and pass outwards from the cells through minute open funnels in the mucilage investment.
Reprouction in Eudorina
Asexual reproduction consists in the formation of daughter colonies within the individual parent cells, whose protoplasts divide up into a number of parts equal to the number of the cells of the ne,y colony. The young colony is at first flat, but finally curls over to form a hollow sphere. This new colony is liberated by the breakdown of the parent cell wall. As all the cells reproduce simultaneously in this way the parent colony naturally disappears after reproduction.
Sexual reproduction is more complex than in Pandarina and shows a definite advance, to oogamy, the gametes being quite distinct in appearance and behaviour. The colonies are generally dioecious, that is to say, the male and female gametes are formed in different colonies. In the female colony the cells enlarge somewhat and become the female gametes, or oospheres, which, when mature, are fertilized in situ. In male colonies the cells divide to form groups of sixty-four antherozoids, yellowish in colour, and each with two flagella. These are liberated as groups which swim to the female colonies, where the antherozoids separate. The zygotes germinate as in Pandorina.

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