I 9 6 PRACTICAL BOTANY 



archegonia : note the directive influence of the archegonia in 

 attracting the spermatozoids to the neck, which they enter, and 

 are lost to sight in the mucilage which fills it. 



MARCHANTIA. SPOROPHYTE. 



XIV. Cut median longitudinal sections of a female receptacle 

 bearing almost mature sporogonia : mount as before, and note 

 under a low power that the parts of the receptacle remain as 

 before : but observe especially 



1. The perigynium, a loose sac-like coat, which arises from 

 the receptacle after fertilization, and envelops the archegonium 

 during its further growth. 



2. The wall of the archegonium, now consisting of two layers 

 of cells, and still bearing at its apex the neck, which shows 

 signs of withering. 



3. The sporogronium, an almost spherical body inclosed by 

 the enlarged venter of the archegonium : the following parts of 

 it are to be recognized 



a. The massive conical foot or seta at the end remote 



from the neck, i.e. directed towards the base of the 

 archegonium. 



b. The wall of the remaining portion of the sporogonium 



(capsule), consisting of a single layer of cells. 



c. The hemispherical sporogenic mass, with no central 



columella : in it may be recognized (i.) the elaters, 

 long spindle-shaped cells, arranged in a fan-like 

 manner as seen in section ; and (ii.) the spores, 

 Mount a small portion of the yellow flocculent mass which 

 escapes on the rupture of a mature sporogonium, and breathe 

 gently on it, observing it the while under a low power : note 

 the hygroscopic movements of the spirally thickened elaters, 

 and the consequent separation and scattering of the spores. 



