MOSS. 



POLYTRICHUM. 



A. SEXUAL GENERATION. (Oophore.) 

 Keeping the specimen moist, observe : 



I. General Characters. 



1. Stem : erect and unbranched (or branching 



only from the base). 



2. Leaves : pointed at one end. Attached to the 



stem without a stalk (i.e., sessile), 



3. Rhizoids : at the base of the stem (often 



hidden by the sand, etc., clinging to them j 

 to see them distinctly, rinse in water). 



4. Flowering heads. 



(a) In male flowers a terminal rosette of stiff 



green leaves (perichsetium) surrounding 

 the antheridia. 



(b) In female flowers a terminal bud formed 



by the folding together of terminal 

 leaves that enclose the archegonia. 

 Sketch. 



II. Histology. 

 1. Stem. 



Remove the leaves near the base of the stem ; until 

 a razor make a thin transverse section, mount in 

 water, and observe : 



(a) The thin epidermis (best seen in young 



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