2 Transactians of the 



hold equal rank with Mosses and Hepaticae; the three classes, 

 Bryinse, or frondose mosses, Sphagninse, or bog mosses, and Hepa- 

 ticinse, or Hverworts (the Laubmoose, Torfmoose, and Lebermoose of 

 the Germans), thus forming one great muscal alliance. 



As it may be of interest to know something of the histology of 

 the Sphagnums, and except the late Mr. Wilson's admirable sketch 

 of the family in ' Bryologia Brit.' we have Httle in our own 

 language bearing on the subject, I purpose on this occasion to point 

 out the chief characters which distinguish them from mosses, and at 

 a future time, with your permission, give an account of all the 

 British species, with illustrative figures of their structure. 



Commencing with the spore, we find that on germination it does 

 not produce the much-branched confervoid prothallium of mosses, 

 but if growing on the wet peat, a lobed fohaceous production results, 

 exactly like one of the frondose Hepaticae, as Anthoceros, and from 

 this the young plants grow. This was fii'st observed by Hofmeister 

 in 1854. If germination occur in water, the prothallium is a fine 

 filament, the lower end of which forms roots and the upper enlarges 

 into a nodule from which is developed the young plant. As soon 

 as branches form on the plants, in both cases the prothallium and 

 roots wither away. Next, the stem, which in mosses consists of uni- 

 form texture throughout, is in Sphagnums much more differentiated, 

 for we observe — 1st, a medulla, or central pith, of long cyUndric cells 

 by which a cm-rent of sap is constantly passing to the growing 

 apex ; 2nd, a woody cylinder of firmer prosenchymatous cells ; and 

 3rd, an outer, or bark-layer of one to four strata of thin walled cells, 

 always larger than the rest, and which in S. eymhifolium alone 

 contain spiral threads and foramina. The branches also are quite 



?ecuhar, and difi'er altogether in arrangement from those of mosses, 

 n the young state they are crowded into a capitulum at the top of 

 the stem, and as the intemodes elongate they become separated, and 

 are then seen to be in lateral fascicles of three to ten, the bundle 

 originating at one side of a leaf base, every fourth leaf in the spiral 

 giving rise to a branch fascicle. 



Of these branches, one part spread out horizontally and then 

 arch down, the rest being attenuated, pendulous, and pressed back 

 to the stem, and by these water is conducted to the very apex ; in- 

 deed. Professor Schimper compares their action to a hydraulic 

 pump, for a tuft of plants placed dry in a flask of water immediately 

 carry on the fluid by the lower bark cells, and empty the flask by a 

 discharge of drops from the down-bent capitulum, but if some of 

 the branches and bark be removed, no passage of fluid takes place 

 beyond the injured part. 



Of the sponge-like retention of moisture by Sphagnums, we have 

 often unpleasant experience when stepping on the green turf-hke 

 surface of its beds, only to plunge deep into their interior, and 



