THE BRYOPHYTES. 173 



the epidermal cells, notice the rows of green parenchyma 

 containing numerous chlorophyl bodies. Determine if 

 starch is present. In the green parenchyma, find air cavi- 

 ties lined with bright green cells. A stoma connects each 

 air cavity with the outer air, but may not lie in the plane 

 of the section. Below the green parenchyma, notice color- 

 less parenchyma extending to the epidermis of the lower 

 side of the thallus. Can you find hairs and scales growing 

 from the lower epidermis ? If so, draw them. 



4. With a razor cut off two cupules. Mount one face 

 up, the other face down, in water, pressing on the cover 

 glass to flatten them down. Notice on the first, under 

 low power, a fringe of teeth ; then examine one of the 

 teeth under high power. What is its shape? Do you 

 find any hairs ? Using the second specimen, examine the 

 lower surface of the mount for hairs. 



Imbed in pith a piece of the thallus bearing cupules 

 and make sections passing vertically through a cupule. 

 Draw the sections under the low power. Examine under 

 low power for gemmae. Under high power, trace the 

 development of the gemmse. They should be found in 

 all stages of growth. 



Examine mature gemmae under both low and high 

 powers. Make out the scar which shows where the 

 gemma was attached to its stalk ; also the two vegetative 

 notches half way up the sides. Draw a gemma. Study 

 also gemmae that have begun to germinate. Gemmae that 

 have been in water for a number of days should be used. 

 Compare with the gemmae that have not germinated. 

 Draw. Sow some gemmae on sand in a moist chamber. 

 Keep in the sunlight. They will sprout in a few days. 

 Watch their development until the characteristic struc- 

 tures of the Liverwort are apparent ; make drawings at 

 intervals. 



5. Study the structure of the antheridial branch. Ex- 



