LIVEEWOET 315 



a thallus, passing through the cupule, and 

 mount in fifty per cent, glycerine. Study the 

 wall of the cupule. What is its structure ? 

 Of how many layers of cells does it consist ? 

 Note the base. Examine the gemmse inside the 

 cupule. To what part of it are they attached ? 

 How are they attached ? In what direction do 

 they stand ? What is the structure of the ped- 

 icel ? Look for gemra« of various sizes. Can 

 you trace them down to two-celled papillee? 

 Study a number of sections to see that a 

 gemma develops from the division of the upper 

 cell of a papilla, while the lower cell remains 

 as the pedicel. Do you find any unicellular 

 papillae ? Draw. 

 2. • The antheridial branch. — Make transverse 

 sections of the stalk. What is its outline ? 

 What is the position of the grooves ? Of what 

 sort of tissue is the stalk composed? Does it 

 have an epidermis ? Do its cells contain chlo- 

 rophyll ? What is the arrangement of • the 

 margins of the groove? Note in the grooves 

 the rhizoids, seen in cross-sections. Are there 

 many or few ? What is their outline ? JSTote 

 the peg-shaped outgrowths projecting into 

 their cavities. Compare this view with a lon- 

 gitudinal view of a rhizoid. Notice also the 

 sections of scales in the groove. Do you find 

 them elsewhere in the section ? Compare with 

 those seen on the under side of the thallus. 

 Draw the section . Select a large, Avell-de veloped 

 antheridial branch, and make a vertical section 

 which passes down through the middle of the 

 receptacle and stalk. Mount in water or giyc- 



