STRUCTURE.] MUSCALS. 107 



which are abortive antheridia. linger and Meyer have 

 found what they call spermatic animalcules in the antheridia 

 of Sphagnum and Hypnum. (Comptes Rendus, vi. 632.) 

 But such bodies appear, notwithstanding their active motion, 

 to be nothing more than loose spires. 



Whatever may be the nature of these organs, there is no 

 doubt of the reproductive functions of the contents of what 

 is named the sporangium, theca, or capsule, which, in Urn- 

 mosses, is a hollow urn-like body, containing sporules : it is 

 usually elevated on a stalk, named the seta, with a bulbous 

 base, surrounded by leaves of a different form from the rest, 

 and distinguished by the name of perichatial leaves. If this 

 sporangium be examined in its youngest state, it will be seen 

 to form one of several small sessile ovate bodies (pistillidia, 

 Agardh ; prosphyses, Ehrhart ; adductores, Hedwig), enveloped 

 in a membrane tapering upwards into a point ; when abortive 

 they are called paraphyses. In process of time the raost 

 central of these bodies swells, and bursts its membranous 

 covering, of which the greater part is carried upwards on its 

 point, while the seta on which the sporangium is supported 

 lengthens. This part, so carried upwards, is named the 

 calyptra : if it is torn away equally from its base, so as to 

 hang regularly over the sporangium, it is said to be mitriform ; 

 but if it is ruptured on one side by the expansion of the 

 sporangium, which is more frequently the case, it is denomi- 

 nated dimidiate. When the calyptra has fallen off or is 

 removed, the sporangium is seen to be closed by a lid termi- 

 nating in a beak or rostrum : this lid is the operculum, and 

 is either deciduous or persistent. If the interior of the 

 sporangium be now investigated, it will be found that the 

 centre is occupied by an axis, called the columella ; and that 

 the space between the columella and the sides of the sporan- 

 gium is filled with sporules. The brim of the sporangium 

 is furnished with an elastic external ring, or annulus, and an 

 interior apparatus, called the peristomium : this is formed of 

 two distinct membranes, one of which originates in the outer 

 coating of the sporangium, the other in the inner coat; 

 hence they are named the outer and inner peristomia. The 

 nature of the peristomium is practically determined at the 



