194 



gamete. The zygospores possess smooth cell-walls and the 

 germination is indirect. 



P. morum (Mull.) Bory is abundant in ponds and ditches all over the 

 country. The cells are 8 15 p in diameter and the colonies 20 42 p. (fig. 76 

 A H). 



Genus Eudorina Ehrenb., 1832. [Eudorinella Lemmermann, 

 1900.] The coenobium is globose or subglobose, rarely ellipsoid, 

 and consists normally of 32 cells distantly arranged within the 



Fig. 77. Eudorina elegans Ehrenb. A, adult colony (x475); B, young colony 

 formed by division of contents of mother-cell ( x 730), from Frizinghall, 

 W. Yorks. C E, development of antherozoid-clusters from mother-cell ; 

 F, antherozoids (after Goebel). 



periphery of a copious mucous investment. The cells are globose, 

 with a single bell-shaped chloroplast containing one or more 

 pyrenoids. Small colonies of only eight or sixteen cells are some- 

 times met with. The cilia (one pair) attached to each cell are 

 parallel until they reach the outer surface of the investment, when 

 they widely diverge. Multiplication takes place as in Pandorina 

 by the division of all the cells of the coenobium to form daughter- 

 cosnobia. Sexual reproduction occurs by the union of fusiform or 

 pear-shaped antherozoids, produced 64 in a cell, with oospheres 

 which are slightly larger than the vegetative cells. The oospores 

 have smooth cell-walls and germination is direct. 



There seems no valid reason for the separation of Lemmer- 



