378 APPENDIX. 



gills develop; the floor becomes thinner as the chamber enlarges, 

 and finally ruptures, exposing the gills. Does any part of this 

 floor (called the veil) adhere to the stalk or the edge of cap on 

 mature fructifications ? 



5. If fresh mature fructifications are available cut away the 

 stalk and place the cap on a piece of black paper,* gills down, 

 resting on the stump of stalk, cover with a tumbler or bell jar, 

 and examine after 24 hours the spore print formed by the great 

 number of spores which have fallen from the surface of the gills. 



6. Demonstration. Cut a very thin transverse section of a gill 

 and show the hymenium covering the surface, with basidia carry- 

 ing the free spores. (Fig. 213.) 



7. Compare with mushroom various other fructifications of 

 related fungi (Hydnum, Boletus, Polyporus, Clavaria). Observe 

 the various forms by which extensive surface is secured for the 

 hymenium. (^f 314, figs. 215, 217, 218.) 



III. BRYOPHYTES. 

 A. THALLOSE LIVERWORT (Marchantia polymorpha). 



Examine an entire plant in water. Observe 



1. The flattened horizontal body {thallus) with central line, the 

 midrib, and thinner wings on each side. 



2. The notched apex (the apical cell is at the base of this 

 notch). (% 59.) 



3. The mode of branching (dichotomous). Examine the tips 

 and find one just branched. Do not confuse with notch of apex; 

 when a tip branches there will soon appear two notches. Does 

 the branch appear on the side of the older thallus, or are the 

 branches equal at first? Are they equal when older? (^f 58.) 



4. The green lens-shaped bodies {brood-buds) growing at certain 

 spots along the midrib, surrounded by an outgrowth which forms 

 a cup-like rim about the cluster. Remove a brood-bud and ob- 

 serve its form, especially in full grown ones the two opposite 

 notches, the growing points. (If 362, fig. 290.) 



5. The air chambers .(areola) of the upper part of the thallus, 

 showing through the skin, best seen in older parts and with a 

 lens. What is their form ? Are they all alike ? (^f 57.) 



* If the gills are light colored ; if dark colored use white paper. 



