V. CRYPTOXEMLVCE^. 1.5T 



conceptacle, simple, or formed of several associated nucleoli. Spores congregated 

 without order in the fertile cells or nucleoli. 



Natural Character. Root seldom more than a mere disc, rarely accompanied 

 by creeping fibres, or forming a prostrate mat from which numerous stems arise. 

 Frond extremely various in size and in outward form, sometimes scarcely an inch 

 in height, sometimes (in the Iridcece) two or more feet in length and breadth. 

 Sometimes it is filiform, and then frequently dichotomous, more rarely pinnately 

 parted ; sometimes a stipes, soon compressed above the base, gradually widens up- 

 wards into an expanded, simple or dichotomous lamina, which is occasionally 

 obsoletely midribbed below. Some laminfe are in such cases proliferous, new 

 frondlets springing either from the surface or apices of the old. Sometimes the 

 frond forms a cylindrical, or moniliformly-constricted, undivided or branching 

 tube, the hollow either filled with air or with loose watery gelatine through which 

 a few filaments are dispersed ; and sometimes it is completely bag-like, much in- 

 flated, ovate or sub-globose. 



The substance of the frond is as various as the form. It is frequently cartilagi- 

 nous, gelatino-cartilaginous, or fleshy, sometimes quite gelatinous ; rarely coria- 

 ceous, and still more rarely membranaceous ; in this last case the membrane has 

 much the substance of parchment. It is usually opaque, sometimes semi-trans- 

 parent, never exhibiting proper articulations to the eye ; but when dissected and 

 thin slices are examined under the microscope, the whole substance of a large 

 majority of the plants of this Order, or a greater or less portion of the frond in 

 the remaining species, is seen to be composed of innumerable, slender, confervoid 

 jilaments, lying in a transparent gelatine, and variously combined together. These 

 filaments are sometimes cylindrical with long articulations, sometimes moniliform, 

 like strings of roundish or oblong beads, and both forms often occur in the same 

 frond. Cylindrical filaments are more commonly found in the middle or medullary 

 portion, and are then always longitudinal in direction, running parallel with the 

 longitudinal axis of the stem or branch. ]\Ioniliform filaments are very common 

 in the periphery or external stratum, wliere they lie at right angles with the longi- 

 tudinal axis, or vertical to the surface of the frond. Sometimes these radiating 

 peripheric filaments issue directly, as lateral branches, from the longitudinal ones of 

 the axis ; sometimes a net-work of anastomosing filaments, or a stratum composed 

 of large, roundish cells, imperfectly ordinated in rows, intervenes: and in a few 

 cases, (as in Callophjllis) the medullary region is composed of large, roundish 

 cells, each cell encompassed by a net-work of very delicate filaments. Such 

 genera conduct us to others in which tlie frond becomes less and less perfectly 

 composed of filaments ; roundish and polygonal cells being more and more intro- 

 duced into its construction. Thus, in the tribe Tylocarpece, the whole central por- 

 tion of the frond is made up of polygonal or honey-combed cells, the perii)]ier3^ 

 alone exhibiting a filamentous character, and even this often in a very imperfect 



