BRYOPHYTES 



105 



is a single layer of sterile cells as a wall about the arche- 

 sporium, which is composed of all the remaining cells of the 

 upper half (Fig. 86, #). It will be noted that the sterile 

 tissue in this sporogonium has encroached upon the arche- 

 sporium, which is restricted to one half of the body. In 

 this case the archesporium has the form of a hemisphere. 



In another liverwort (Jungermannia) the archesporium 

 is still more restricted (Fig. 87). The sterile tissue is organ- 



FIG. 87. Diagrammatic section of spo- 

 rogonium of a Junrjermannia form, 

 showing differentiation into foot, 

 seta, and capsule, the archesporium 

 restricted to upper part of sporoso- 

 nium. After GOKBKI,. 



FIG. 88. Section through sporogonium of 

 Sphagnum, showing capsule (k) with 

 old archeironium neck (ah), calyptra (ca), 

 dome-shaped mass of sporogenous tissue 

 (spo), and colnmella (>). also the bulb- 

 ous foot (spf) imbedded in the pseudo- 

 podium (ps). After SCHIMPEK. 



ized into a foot and a seta, and the archesporium is a com- 

 paratively small mass of cells in the upper part of the 

 sporogonium. 



In another liverwort (Antlwceros) the sterile tissue or- 

 ganizes foot and seta, and the archesporium is still more 

 restricted (Fig. 86, D). Instead of a solid hemispherical 



