THE PLANT GROUPS 



105 



Do you find stomata? What kind of tissue is 

 below the green chlorenchyma ? What is its 

 function ? Outline the section and detail a small 

 portion of its cellular structure. Label correctly. 

 Summarize the adaptations of the thallus of the 

 liverwort for photosynthesis and absorption. 



FIG. 22. A common liverwort (Marchantia) 



A, antheridial plant; I], archegonial plant, rh, rhizoids, and m, midrib, of the 

 leaf like flattened body /; c, capsules in which vegetative reproductive buds are 

 formed ; s, upright stalks (a, antheridial and ar, archegonial, the latter being dis- 

 tinguished by peculiar rays r). Slightly more than natural size. From Bergen 

 and Caldwell's " Practical Botany " 



c. Storage and conduction. Are there any such structural 

 devices for storage of reserve foods and for conduc- 

 tion of water and foods in liverworts as we have 

 found in the higher plants ? Be able to explain. 

 4. Reproduction. If Marchantia is used for the following 

 study, the peculiar reproductive branches (receptacles) 

 will need to be explained by the teacher. 

 a. Distribution of sex organs. 



(1) Study the distribution of sex organs on the dorsal 

 surface of the thallus in llicciocarpus, ConocepJmlus, 



