

MUSCI AND HEPATICiE 



OP THE 



UNITED STATES 



EAST OF THE MISSISSIPPI. 



Ordee 139. MUSCI. (Mosses.) 



Low, tufted plants, always with a stem and distinct (sessile) leaves, pro- 

 ducing spore-cases wMcli open by a terminal lid (except in Nos. 1-4), and 

 contain simple spores alone. Reproductive organs of two kinds: 1. The 

 sterile (male) flower, consisting of numerous (4 - 20) minute cylindrical 

 sacs (aniheridid) which discharge from their apex a mucous fluid filled with 

 oval particles, and then perish. 2. The fertile flower composed of numer- 

 ous (4 - 20) flask-like bodies (arc7iegonia,pistiUidia), each having a membra- 

 nous covering (calyptrd), terminated by a long cylindrical funnel-mouthed 

 tube (style) . The ripened archegonium (seldom more than one in a flow- 

 er maturing) becomes the capsule, which is rarely indehiscent or splitting 

 by 4 longitudinal slits, but usually opens by a hd (operculum) : beneath the 

 operculum, and arising from the mouth of the capsule, are commonly 1 or 2 

 rows of rigid processes (collectively the peristome) which are always some 

 multiple of four : those of the outer row are called teeth ; those of the 

 inner row, cilia, their intermediate smaller processes, ciliolce. An elastic 

 ring of cells (annulus) lies between the rim of the capsule and operculum. 

 The powdery particles filhng the capsule are spores or sporules. The 

 thread-hke stalk (pedicel) supporting the capsule is inserted into the elon- 

 gated torus (vaginula) of the flower. The pedicel continued through the 

 capsule forms the columella ; when enlarged uniformly under the capsule, it 

 forms an apophysis ; when protuberant on one side only, a struma. The 

 calyptra separating early at its base is carried up on the apex of the cap- 

 sule ; if it splits on one side it is hood-shaped "or cuculliform, if not, it is 

 mitre-shaped or mitriform. Intermixed with the reproductive organs are 

 cellular jointed filaments (parapJiyses) . The leaves surrounding the an- 

 theridia are called the perigonial leaves ; those around the archegonium or 

 pedicel, the perichcetial leaves. 



