AND BUXBAUMIA. 335 



different states, to ascertain absolutely the cEconomy of this 

 moss in the dispersion of its seeds. It is evident, however, 

 if the description already given be correct, that as far as 

 dispersion takes place, by the mouth of the capsule, it can 

 only be effected by a contraction or shortening of the colu- 

 mella, and a corresponding retraction within the cavity of 

 the capsule, of the central portion of the periatomium which 

 adheres to it; and in this state several of the specimens 

 were actually found. 



But it is also manifest, both from the great size of the 

 columella, and its numerous points of connection with the 

 inner membrane, that in this way the whole of the seeds 

 cannot be discharged. It is possible therefore, that in cer- 

 tain circumstances at least, their dispersion may be assisted 

 by the minute pores existing at the base of the capsule. 

 These pores, in the specimens examined, were found to 

 penetrate the outer membrane, or even its external layer 

 only, and being situated below the origin of the seminal 

 bag, their first effect will probably be to accelerate the 

 decay of the internal spongy texture of the base of the pes 

 capsule. But by thus removing support from the colu- 

 mella and inner membrane, they may contribute to the 

 greater shortening of the former, and consequently in 

 increasing the dispersion by the mouth of the capsule ; or, 

 from the same cause, the inner membrane being at length 

 ruptured, the seeds may be in part discharged by the pores 

 themselves. 



It seems then not improbable, from what we at present 

 know of the structure of Lyellia, that for the dispersion of 

 the seeds in this genus there are two distinct contrivances, 

 both of which, however, in the only species yet known, are 

 apparently imperfect. But hence it is perhaps allowable to 

 conjecture, that either other species of Lyellia, or a nearly- 

 related genus may exist, in which while the mouth of the 

 capsule remains absolutely shut, the pores of the base may 

 be sufficiently enlarged for the complete performance of this 

 important function. 



Pores exactly resembling those of Lyellia crispa have not 

 hitherto been found in any other moss. I have observed. 



