ALGJE 



99 



posed of multitudes of spherical cells, each cell representing 

 a complete Gloeocapsa body. One of the peculiarities of the 

 plant is that the outer part of the cell 

 wall becomes mucilaginous, swells, 

 and forms a jelly-like sheath. Among 

 the cells examined there will be found 

 some that are dividing, a wall extend- 

 ing across the spherical cell and di- 

 viding it into hemispheres. Each 

 hemisphere is a new plant which 



FIG. 92. Glceocapsa: show- 

 ing single cells, and small 

 groups that have been 

 formed by division and 

 are held together by the 

 enveloping mucilage. 



grows as large as the 

 parent cell .and then 

 divides in turn. The 

 mucilaginous walls hold 

 the cells together, and 

 so they are found in 

 groups of various sizes 

 (Fig. 92). This method 

 of reproduction by cell- 

 division is the simplest 

 kind of reproduction. 



> 59. Nostoc. These 

 plants occur in jelly- 

 like masses in damp 

 places. If the jelly be 

 examined, it will be 

 found to contain em- 

 bedded in it numerous 



IFic. 93. 4, Nostoc: showing the chain-like fila- 

 ment and a heterocyst (a) ; B. Glceotrir/nn: 

 showing mucilage sheath, basal heterocyst. 

 and tapering apex. 



