. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. 84 MOSSES AND FERNS CHAP. dorsal lamina or wing, which may be more or less spirally placed, owing to torsion of the axis, but this torsion was much exaggerated in the early figures of the original species, R. helicophylla. According to Goebel's investigations, the grow- ing point is formed secondarily, and this statement is con- firmed by Howe's studies. The latter writer has studied the germination of the spores and has described the formation of gemmae in R. Americana. The latest contributio
. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. 84 MOSSES AND FERNS CHAP. dorsal lamina or wing, which may be more or less spirally placed, owing to torsion of the axis, but this torsion was much exaggerated in the early figures of the original species, R. helicophylla. According to Goebel's investigations, the grow- ing point is formed secondarily, and this statement is con- firmed by Howe's studies. The latter writer has studied the germination of the spores and has described the formation of gemmae in R. Americana. The latest contribution to our knowledge of Riella is that of Porsild (i). He confirms Howe's statements and has. Fig. 36.—a, D, Riella Americana; B, C, R. helicophylla; A, Apex of female plant, X8; B, C, lateral and ventral view of the growing point, X500; x, apical cell ;£., leaves. D, male plant, XiH; fA, D, after Howe; B,C, after Leitgeb.) further investigated the question of the growing point. He finds that while an apical cell is absent in the younger stages, it is formed later in normal plants. Both archegonia and antheridia resemble those of Sphcero- carpus very closely, and the structure of the sporophyte is also the same, no true elaters being developed, but instead there are simply sterile Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Campbell, Douglas Houghton, 1859-1953. New York, The Macmillan Company;
Size: 1744px × 1432px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcampbelldouglashought, bookcentury1900, bookdecade1910
