310 THE BIOLOGY OF THE PLANT 



female stalks occur on the same plant ? Are 

 they always borne upon the same side of the 

 thallus ? Do you always find the same number 

 on each plant ? What is their relation to the 

 midrib ? What is the shape of the stalk of the 

 fruiting branches? Look for grooves running 

 lengthwise along the stalk. How many do 

 you find ? What is their position ? Examine 

 both surfaces of the expanded portion or recep- 

 tacle of each. Note the ridges on the receptacle 

 of the antheridial stalks. How many are there ? 

 Are they on both sides ? Compare in all re- 

 spects with the archegonial branches. Look for 

 the two kinds of fruiting branches in different 

 stages of growth. What changes in shape and 

 size do they go through in the course of their 

 development ? 



Look closely at the upper surface of the thal- 

 lus for small, cup-like outgrowths, the cupules. 

 What is their position? Does it have any par- 

 ticular relation to the midrib or to any other 

 part of the thallus ? Are the cupules evenly dis- 

 tributed over the surface ? What is their shape ? 

 Look for small, green, non - sexual reproductive 

 bodies, the gemmae, inside the cupules. Do all 

 of the cupules contain gemmse ? Are the cupules 

 borne upon a stalk ? Are they borne upon the 

 same plants as have the fruiting branches ? Do 

 you also find cupules upon plants which bear no 

 fruiting stalks? With a hand -lens examine a 

 cupule and note the shape of its margin and the 

 position of the gemmte. With a lens study the 

 upper surface of the thallus and note that it is 

 marked ofl' into small areas, the areolae. In 



