374 



MUSCI. 



Gymnostoma have certainly affinity in habit and in the 

 form of theca with Splachnoideae. 



Among several hypothesis that may be framed to reduce 

 the singularity of the structure to something like the usual 

 type, perhaps that is the most curious which is grounded 

 on the developement of the seta, which resembles strongly 

 in its earlier stage the developement of a phaenogamous ovule ; 

 the question never arises, to what degree can the capsule, and 

 frequenty its highly complicated apparatus be made to assi- 

 milate with our notions of the structure of a seed, for the 

 capsule is the produce of fecundation, applied to a pre-exist- 

 ing ovulutn. 



In this point of view the seta is the radicle, and it presents 

 a remarkable structural, and a remarkable physiological 

 affinity with the more perfect radicles of flowering plants, for 

 the apex of the radicle is the first formed, and is not sub- 

 jected to any particular subsequent change of structure. And 

 as to functional analogy, the fruit of a moss is alone in com- 

 munication with the foliaceous organs, by means of its seta, 

 this communication not being one of continuity, but of mere 

 contiguity. Its apex is likewise formed according to re- 

 ceived notions of the structure of radicles, it certainly is, un- 

 til hardened by age, the softest part of the tissue of a moss. 



The main objection to this view is, the extraordinary com- 

 plication of structure, to which we know nothing analogous, 

 because the curious fact of a radicle, germinating in pericarpio 

 is by no means without a parallel (for the rupture of the 

 ovary has analogies) although perhaps it is in the direction 

 the radicles takes, and in its rooting in the axis that gave it 

 origin. 



Nor will the opercular dehiscence perhaps be found to be 

 unrepresented among Phrenogams, as the plurality of em- 

 broys, or bodies capable of reproducing the species characte- 

 rises a whole tribe of Dicotyledons. 



The curious analogies above alluded to, are distinctly percep- 

 tible, but anomalies remain which are quite unexplainable, in 



