. The structure and development of mosses and ferns (Archegoniatae). cia, is strictly acropetal. The first stages are exactly likethose of Riccia, and the primary cell divides into two cells, apedicel and the antheridium proper. The divisions in the lower so MOSSES AND FERNS CHAP. cell are somewhat irregular, but more numerous than in Riccia,so that the stalk of the ripe antheridium is more massive(Fig. i6). In the upper cell a series of transverse walls isformed, varying in different species in number, but more thanin Riccia, and apparently always perfectly horizontal. InMarchantia polymorpha
. The structure and development of mosses and ferns (Archegoniatae). cia, is strictly acropetal. The first stages are exactly likethose of Riccia, and the primary cell divides into two cells, apedicel and the antheridium proper. The divisions in the lower so MOSSES AND FERNS CHAP. cell are somewhat irregular, but more numerous than in Riccia,so that the stalk of the ripe antheridium is more massive(Fig. i6). In the upper cell a series of transverse walls isformed, varying in different species in number, but more thanin Riccia, and apparently always perfectly horizontal. InMarchantia polymorpha Strasburger (2) found as a rule butthree cells, before the first vertical walls were formed. In anundetermined species of Fimhriaria (Fig. 15) probably , the antheridia were unusually slender, and fre-quently four, and sometimes five transverse divisions are formedbefore the first vertical walls appear. Sometimes all the cellsdivide into equal quadrants by intersecting vertical walls, butquite as often this division does not take place in the uppermost.
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Keywords: ., bookauthorcampbelldouglashought, bookcentury1900, bookdecade1910
