ANTHOCEROS. 97 



3. That the structure is organized into three regions, an 

 outer protecting, supporting, and chlorophyll-bearing 

 region; an axial region; and between these the spore- 

 forming or sporogenous region. 



4. In the sporogenous region, the stages in the process of 

 spore formation, from youngest sporogenous tissue in the 

 lower part of the sporophyte, to fully formed spores toward 

 the tip. 



5. Draw, showing different kinds of tissues, and stages in 

 spore formation. 



ANNOTATIONS. 



The gametophyte body of Anthoceros is very much 

 more simple than that of Riccia. It has no special air- 

 chambers or air-pores, is but a few layers of cells in thick- 

 ness in the thickest place, and in every way suggests a 

 very simple type of plant-body. The archegonia and 

 antheridia are simple in structure. The archegonia 

 develop from surface cells and become surrounded by 

 gametophyte tissue while antheridia are endogenous in 

 origin. The fertilized egg begins its development while 

 imbedded in the archegonium. From this oospore there 

 develops a sporophyte which is much more complex than 

 any heretofore considered. The sporophyte is distinctly 

 stalked and bears at its lower end structures like short 

 rhizoids which serve to increase the surface through 

 which the foot absorbs nourishment from the gameto- 

 phyte. In addition to this there are stomata, like those 

 of higher plants, and chlorophyll that enables the sporo- 

 phyte to manufacture some of its own food. It is evi- 

 dent that the sporophyte is somewhat independent, and 

 to become completely so it needs but to have the root- 



