MUSCI. 



373 



succeeding ones from its last segments, in the same manner as the antheridia of 

 the same genus, and those of Radula and Fontinalis. According to preparations 

 which Schuch obtained in the laboratory at Wiirzburg, the first archegonium 

 arises also in typical Mosses from the apical cell of the shoot. 



The order of succession of the cells in the development of the archegonium 

 has been studied by Kiihn in AtidrecBa, and by Janczewski in the Phascaceae, Bryinese, 

 and in Sphagnum. As in the Liverworts so here also, the whole archegonium is 

 derived from an outgrowth of a superficial cell of the punctum vegetationis. This 

 is divided by a transverse wall [nim, Fig. 255 yi) so as to form a lower cell 

 (corresponding to the pedicel of the Liverworts) and an upper external cell, in 



Fig. 255. — First stage of development of the archego- 

 nium oi Ancire^a (after Kiihn); A terminal archegonium 

 arising from the apical cell of the shoot ; b b the youngest 

 leaves ; B after the formation of the central cell and stig- 

 matic cell; C transverse section of the j'oung ventral 

 portion. 



'?lC,.rz<,(i.—Fiinaria hygrometrica ; A longitudinal section of the summit of a weak female plant (Xioo), a archegonia, 

 * leaves; B an archegonium (X 550), b ventral portion with the oosphere, h neck, nt mouth still closed; the canal-cells are 

 beginning to be converted into mucilage (the preparation had lain three days in glycerine) ; C the part near the mouth of the 

 neck of a fertilised archegonium, with dark red cell-walls. 



which, as in the corresponding cell of the antheridium, two oblique walls inclined 

 in opposite directions appear. The two oblique cells thus cut off give rise, at a 

 later period, to the tissue of the lower part of the ventral portion of the archegonium, 

 which is here more developed' than in the Liverworts (Fig. 256, B). The upper 

 cell undergoes the same divisions as it does in the Liverworts; the mode of 

 formation of the ventral wall and of the central cell is the same in this group as 

 in that; but the formation of the neck is here quite different. Whereas in the 

 Liverworts the first transverse division of the internal cell produces an upper cell 

 which at once represents the * stigma' of the archegonium, the cell thus formed 



