The Study of the Biology of Ferns by the Collodion Method; For Advanced and Collegiate Students

by George Francis Atkinson

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1894 ...to the annulus. The figure, therefore, shows an oblique section through the wall. Fig. 117 is from a section of the annulus of Aneimia phyllitidis. The section is perpendicular to the inner wall, but not to the entire extent of the annulus. Osmundaceae.--The sporangia are rounded, obovate, shortstalked, or sessile. They are asymmetric, possessing a very simple annulus on the dorsal surface of the broad vertex. The eters radiating from the vertical side Fie. 118. Dorsal view of the 13. _ J 1.. 4.U 1 1 1.1 with lignified walls, farther down by cells similar to those of the lateral walls of the sporangium. The cells bordering the annulus below and overlapping its cells have their walls lignified for a short distance at the point of union with the annulus. The internal walls of the annulus are very thick and form a stout plate upon which the bases of the fulcra of the annulus are fixed. The fulcra, the longer or transverse walls of the annulus, are shown in transection of the sporangium (longisection of the annulus) to be quite broad at the base, tapering outward to a rather thin edge at their union with the superficial wall, appearing in the section narrowly triangular. The entire narrow, elongated cells with lignified walls, which mark the line of cleavage of the sporangium, extend perpendicu % lar to the annulus, several in parallel m rows, down on the front of the sporanJ gium, which bellies out from the short pedicel or point of attachment. The cells of the annulus form about two rows transversely across the dorsal side of the vertex, their longer diamlongisection of the annulus presents a crescent figure, the convexity of which is more strongly curved than the concavity, while the intervening perpendicular fulcra become shorter from the middle toward each...

36 pages, Paperback

First published September 27, 2015

About the author

1854-1918