309 



factory than those of Agardh ; perhaps they are : but their fault is evidently 

 that of being too hypothetical, and of not- distinctly deciding the position 

 of Hepaticce. 



Struck, perhaps, with this objection, M. Adolphe Brongniart has more 

 recently proposed .a triple division of Cellular plants, in the following 

 manner : — I. Neither vessels nor foliaceous appendages ; no trace of sexual 

 organs; sporules contained in indehiscent capsules, or bursting irregularly, 

 with no- kind of proper integument. These answer to the Acotyledones of 

 Agardh and the Homonemea of Fries. II. No vessels, but foliaceous 

 appendages ; sexual organs doubtful ; sporules contained in great numbers 

 in capsules that burst regularly, and having a proper integument. Ex. 

 Hepaticae and Mosses. III. Vessels present, and foliaceous appendages; 

 sexual organs certainly existing in some ; sporules contained in polysper- 

 mous and dehiscent, or monospermous indehiscent 'capsules. Ex. Ferns 

 and their allies, with Chara.— To the definitions of these, several objections 

 might be taken, particularly to all that part which relates to the supposed 

 presence of sexual organs ; but the divisions themselves appear less excep- 

 tionable than any others that have been proposed. They are therefore adopt- 

 ed here, with such an alteration of their definitions as will render them less 

 open to criticism. They are in conformity with the view that has been taken 

 of the subject by Nees v. Esenbeck, in his and Ebermaier's excellent Medical 

 B,otamj, which only reached me after the whole of the preceding matter had 

 been written. 



Flowerless plants may be considered to exist in three principal forms: 

 first, those in which a distinct vascular system exists ; secondly, those in 

 which no vascular system exists, but which have a central axis of develope- 

 ment; and thirdly, those which have .neither a vascular system nor a central 

 axis, but are mere homogeneous masses ramified irregularly. The two former 

 have their reproductive bodies, or sporules, arranged in cases provided for their 

 elaboration and ultimate dispersion ; in the latter the sporules lie in the sub- 

 stance of the plant, and can only be disseminated by its destruction. These 

 may be called Fern-like^ Moss-like, and Leafless Flowerless Plants. 



