DIRECTIONS FOR LABORATORY STUDY. 381 



ized making an open canal to the ei;g, and others, perhaps, with 

 an embryo sporopliyte in the enlarged body. {^391, fig- 331.) 



14. Demonstration. From a mature capsule mount and show 

 spores and elaters. (Fig. II, A.) 



C. MOSS (Mnium cuspidatimi). 



Examine plants with capsules attached. Observe the two 

 connected plants : 



1. The leafy stemmed plant 01: gametophyte. (1 55.) 



2. The slender plant attached to its tip, the sporophyte, consist- 

 ing of a wire-like stalk, the seta, enlarged above to form the 

 hanging capsule. ("^IT 67. 322.) 



3. Boil for a few minutes in 5 per cent, potassic hydrate, rinse 

 in water and gently pull sporophyte until it separates from the 

 gametophyte. Observe the smooth pointed end which was sunk 

 in gametophyte. If properly separated no sign of tearing can be 

 seen. (Fig. 73.) 



Examine gametophyte in water. Observe 



4. The differentiation of the body into stem and leaves. 



5. The brown hairs (rhizoids) about the stem, which attach 

 plant to ground. Do they branch ? (1[ 52.) 



6. The strength of the stem ; test it by breaking it with a 

 lengthwise pull. Cut a thin transverse section and observe dark 

 colored mechatiical tissues in outer region. (1163. fig. 68.) 



7. The form and structure of the foliage leaves ; note midrib 

 of mechanical cells (test strength); lamina of one layer of cells 

 large enough to be visible under lens ; border oi mechanical cells, 

 some projecting pretty regularly as teetli. (^64, fig. 69.) 



8. Smaller, scale-like leaves on part of the stem. 

 Examine sporophyte with mature capsule. Observe 



9. The slender seta. 



10. The thin yellow inverted capsule, from whose end a piece 

 has fallen leaving it open. (1322, fig. 72.) 



11. About the edge of the capsule a fringe of pointed projec- 

 tions, teeth, curved inward, constituting the peristome. Break off 

 these outer teeth and notice the pale fringed membrane within, 

 forming the inner peristome or oidostome. (Figs. 72. 231.) 



12. Among these, or to be pressed out of capsule, many fine 

 spores. 



13. Demonstration. Cut off on a slide the end of the capsule as 

 a ring, with peristome attached. Divide this ring into halves. 



