ARCHEGONIUM OF MARCHANTIA. 



343 



at its edges, which protects the entire row of archegonia. Nume- 

 rous cells of this contain oil-bodies. 



Fertilisation. It is comparatively easy to see the opening of 

 the archegonium take place under the microscope. We take 

 quickly longitudinal sections through a female inflorescence, which 

 has not yet raised itself, or only t a little, upon its stalk, lay it dry 

 under a cover-glass, and examine it under the microscope. When 

 we appear to have found a ripe archegonium, and while still 

 keeping it in view, 

 we place a drop of 

 water at the edge 

 of the cover - glass. 

 After the entrance 

 of this, the arche- 

 gonium opens al- 

 most immediately. 

 The cause of the 

 opening lies in the 

 strong swelling of 

 the contents of the 

 neck - canal. The 

 neck - cells separate 

 from one another at 

 the apex of the neck. 

 The contents of the 

 neck canal-cells pass 

 out, then the con- 

 tents of the ventral 

 canal - cell follow. 

 The homogeneous 



portion of these con- FIG. I2LMarchantia polymarpha. A, young; B, 



opened archegonium ; C, fertilised archegonium after the 



tents IS iormed Of commencement of the formation of the embryo. IS, neck 



i <*trnncrlv dwpllino- ^-anal-cells ; k", ventral canal-cell ; >, oosphere ; pr, peri- 

 3ngl\-s\\el mg anthium(x 540)> 



slime, which diffuses 



in the surrounding water; the granular contents remain in the 

 surrounding water, where they are slowly disorganised. Immedi- 

 ately after the ejection of the ventral canal-cell, the oosphere in 

 the central part of the venter rounds off (Fig. 124, B). At its 

 anterior margin, i.e., that in apposition to the canal, a clearer 

 spot, the receptive-spot, is often, though not always, to be 

 distinguished. 



