86 MARCHANTIA POLYMORPHA. 



within each area. Lunularia cruciata is not uncommon 

 in greenhouses. It may be distinguished by its crescent- 

 shaped cupules, lacking a border on one side. 



Marchantia may be grown in the laboratory. In 

 collecting material for study, care should be taken to 

 obtain fertile plants with young heads; some female 

 heads just large enough to be seen in the sinus at the 

 tip of the branch should be collected. Also a good 

 supply of older heads of both flat and radiate forms will 

 be needed. 



LABORATORY WORK. 



GROSS STRUCTURE. 



I. VEGETATIVE STRUCTURE. By examining one or two speci- 



mens, observe: 



1. The general form and color of the body. 



2. Its manner of branching. 



3. The rhizoids. 



4. The diamond-shaped areas, with a central air-pore in each. 

 These are seen best with a small lens. 



5. Draw. 



II. REPRODUCTIVE STRUCTURES. Observe: 



1. In rather large patches of Marchantia note how the younger 

 parts of the plants have advanced, and have been left free 

 as new plants by the death of the older portion. 



2. Two kinds of heads on the upright branches. The flat 

 disk-like one is the anther idial head, and the radiate or 

 fingered one is the archegonial head. Determine whether 

 both kinds are borne on the same plant. 



3. The cupules, their form, and where borne; the small green 

 buds, the gemma:, within the cupules. 



4. Make general sketches illustrating reproductive structures. 



