MICROSCOPIC FORMS OF VEGETABLE LIFE. 



257 



the ordinary filamentous cells developing oospores on the one hand, and 

 antherozoids on the other; and in the simplicity of the means by which 

 the fecundating process is accomplished. 



254. The (EdogoniecB resemble Confervacece in general aspect and 

 habit of life, but differ from them in some curious particulars. As the 

 component cells of the filaments extend themselves longitudinally, new 

 rings of cellulose are formed successively, and intercalated into the cell- 

 wall at its upper end, giving it a ringed appearance. Only a single large 

 zoospore is set free from each cell; and its liberation is accomplished by 

 the almost complete fission of the wall of the cell through one of these 

 rings, a small part only remaining uncleft, which serves as a kind of 

 hinge whereby the two parts of the filament are prevented from being 



JL. Sexual generation of CEdogonium ciliatum : 1, filament with two oospores in process of 

 formation, the lower one having two androspores attached to its exterior, the contents of the 

 upper one in the act of being fertilized by the entrance of an antherozoid set free from the interior 

 of its androspore; 2, free antherozoids; 3, mature oospore, still invested with the cell-membrane 

 of the parent filament ; 4, portions of a filament bearing sperm cells, from one of which an andro- 

 spore is being set free; 5, liberated androspore. 



B. Branches of Chcetophora elegans, in the act of discharging flagellated zoopores, which are 

 seen, as in motion, on the right. 



altogether separated. Sometimes the zoospore does not completely extri- 

 cate itself from the parent-cell; and it may begin to grow in this situa- 

 tion, the root-like processes which it puts forth being extended into the 

 cavity. Professor A. M. Edwards (U. S.) states that he has seen the 

 so-called ' motile spores ' of the CEdogonium develop into objects exactly 

 resembling Euglence, and finally reproducing "a, filament exactly like 

 that from which the original green spore was projected." He further 

 asserts he has seen the cell-contents of CEdogonium develop into forms 

 identical with several genera of Ehrenberg's Polygastric Animalcules. 1 



17 



Monthly Microsc. Journal," Vol. viii. (1872), p. 28. 



