100 MORPHOLOGY AND LIFE HISTORY 



observe the attachment of the sporophyte to the 

 receptacle by means of the foot. This study may be 

 made to advantage with fresh or preserved material 

 teased out on the slide. In such preparations there 

 will be observed, surrounding the sporogonium, the 

 membrane formed by the growth of the perigynium. 



2. In the mount already made (or in a fresh mount of 

 the orange-colored mass referred to in (B, i, p. 99), 

 observe the spore-mother-cells (sporocytes) or, in 

 older specimens, the spores (in strands or separate, 

 depending on the stage of development), and the 

 elongate elaters. What is the size of the spores, and 

 the number of cells of which they are composed? 

 Describe their shape, and any surface marks ob- 

 served. Describe any marks on the craters. Of 

 how many cells is an elater composed ? Mount, dry, 

 some of the mass that contains elaters, and observe, 

 under the low power, their behavior as water is 



added. Draw. 



3. Are the antheridiophores and archegoniophores 

 sexual organs ? Why ? What are the sexual organs 

 of Marchantia? 



4. Name and classify (sexual or asexual) four different 

 kinds of reproductive bodies produced by this plant. 

 Consider carefully whether the spores, produced 

 by the sporophyte, are sexual or asexual reproduc- 

 tive bodies. 



D. Physiology: 



1. Can photosynthesis take place in the sporophyte? 

 Explain your answer. 



2. From what source, by what organ or organs,. and 

 by what physical process does the sporophyte ob- 

 tain its water and dissolved food? Compare it 

 with the gametophyte in this respect. 



