[5] 75 LIVERWORTS 



Pellia. 



A. Examine a plant of Pellia (a common Liverwort). Sketch the form of the flat green branching thallus, 

 with a thickened midrib attached by rhizoids to the soil. 



B. Draw a transverse section through the thallus, shewing the uniform parenchymatous thin-walled tissue, 

 containing numerous chloroplasts, especially towards the upper surface, and starch grains ; also rhizoids arising 

 from the lower surface and penetrating the soil. 



C. Examine and draw a section through the spore capsule shewing capsule wall, spores and elatcrs. 



D. Examine a ripe spore-capsule. Note the four valves into which the capsule splits. Examine some of 

 the brown spores in dilute glycerine under the high power. 



