CylindrocapsacedR 



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somewhat peculiar member of the Ulotrichales for which it is necessary to provide the 

 special family Microsporaceae. 



The germination of the akinetes has been studied by the present author. When kept 

 in water it was found that they remained alive and apparently unchanged for a period of 

 about two years, after which a small percentage germinated. The germination proceeded 

 in one of two ways : (1) the protoplast divided into four as it escaped from the old wall of 

 the akinete, four rounded cells being set free, each of which grew into a new filament 

 (fig. 186 D and E) ; (2) the protoplast escaped without any division from the old wall, 

 and divided first into two and then into four cells tetrahedrally arranged, each cell on 

 becoming free developing into a new filament (fig. 186 F 7). 



If the akinetes were allowed to become dry for a period of a week or ten days, soon 

 after their formation, and then placed in water they germinated very readily. Each one 

 elongated, the thick wall became largely mucilaginous, and transverse divisions soon 

 resulted in a new filament (fig. 186 A (7). This quick germination is entirely different 

 from the belated type which takes place when the akinetes are never allowed to dry, and 

 indicates that a period of drought is favourable for their proper development. 



H 



I 



Fig. 186. Germination of the akinetes of Microspora floccosa (Vauch.) Thuret. A C, direct 

 germination of akinete in water, after having been dried for ten days. D I, germination 

 of akinetes after a resting period of two years during which they were never allowed to become 

 dry ; D and E, first method of germination ; F I, second method of germination. All x 850. 



Family Cylindrocapsaceae. 



This family includes the single genus Cylindrocapsa Reinsch ('67), 

 concerning which our knowledge is as yet in many ways defective. The 

 thallus is filamentous and unbranched, with the cells arranged in a single 

 series. The filaments are short and in some respects they resemble those 

 of the more mucilaginous types of the Ulotrichaceas. The cells are ellipsoid, 

 subrectangular or less often subtriangular in shape, and they are frequently 

 grouped in pairs at short intervals along the filament. They are provided 

 with a firm cell-wall outside which are several mucilaginous lamellae, and the 

 row of cells comprising the filament is enclosed within a cylindrical, close- 

 fitting sheath of tough mucus (fig. 187 E and F). The general arrangement 



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