BOTltYDIACEJU. Ill 



ORDER III. SIPHOPHYCEJE. 



Unicellular algse, usually at the time of fruiting bicellular. 

 Cells utricle-shaped, often prominently branched ; branches with 

 terminal vegetation, at length shut off by a septum, some trans- 

 formed into oosporangia, others into antheridia. Cell contents 

 green, mucilaginous, granulose, filled with chlorophyllose vesicles 

 and starch granules. 



Propagation by free cell formation, or zoogonidia, or 

 oospores. 



Plants aquatic or terrestrial, some marine. 



FAMILY I. BOTRYDIACE.E. Propagation by free cell for- 

 mation and by zoospores. 



FAMILY II. VAUCHERIACEJE. Propagation by oospores 

 and zoogonidia. 



FAMILY I. BOTRYDIAOE^J. 



Plants small, terrestrial, unicellular. Cell in the beginning 

 globose, afterwards clavate or pyriform, and inflated ; vertex 

 rounded, a long time closed, attenuated downwards ; base 

 divided into delicate hyaline radicles, filled within with a 

 mucilaginous green granulose cytioplasm, with age collapsing 

 at the apex, and finally wasting away. Cell contents modified 

 into an indefinite number of resting spores ; spore contents, in 

 germinating, becoming modified into a number of sexual zoo- 

 spores conjugating and forming isospores. 



GENUS 52. BOTRYDIUM. Wallr. 



Vegetative plants unicellular, increasing by cell division and 

 zoospore formation ; asexual uniciliate zoospores ; sexual bici- 

 liate isospores, sometimes globular, and alike capable of 

 germination, sometimes compressed and hexagonal, furnished 

 with a few.tuberculate thickenings. 



See for information Braun's " Rejuvenescence," pp. 128, 193, 220, 

 274 ; Parfitt in " Grevillea," Vol.i., p. 103 ; Archer in " Grevillea," Vol. 

 i., p. 105 ; Eostafinski and Woronin, " Ueber Botrydinm granulatum," 

 1877; Lawson in "Trans. Bot. Soc., Edinburgh," vi., 424 ; Archer in 

 " Quarterly Journal of Microscopical Science/' 1878, pp. 446-452. 



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