CRYPTOGAMOUS PLANTS. 231 



Davallia, Asplenium, &c, the male organs are upon 

 the same leaves as the capsules. 



The theories of Hedwig and Bernhardi are at present 

 the only ones which deserve attention, but I will not 

 venture to say any thing upon the preference which 

 ought to be given to either of them : that of Bernhardi 

 presents, it is true, less objections ; but the facts upon 

 which he rests are known in so small a number of 

 species, and have been observed so little in detail in 

 those where they have been described, that it appears to 

 me premature to adopt them without new examinations. 



As soon as the leaf is developed, the male organs 

 (I here speak collectively in the sense of the two hypo- 

 theses) disappear, and the female organs begin to in- 

 crease. We see them gradually become elevated, and 

 afterwards, at maturity, they break the pellicle which 

 covers them ; the clusters bear the name of Sori, and 

 their integument that of Indusium; the disposition of 

 the clusters upon the limb or margins of the leaf, and the 

 existence or form of the indusium, are the principal cha- 

 racters from which the classification of Ferns is derived : 

 let us examine now the bodies of which the clusters are 

 composed. 



These bodies, at maturity, are of a brown or reddish 

 colour, round or reniform, and furnished with a short 

 pedicel. The name of Capsules, or more correctly that 

 of Sporangia, is given to them; they are most fre- 

 quently bordered with an elastic ring, which opens from 

 within outwards, and causes the dehiscence of the cavity ; 

 in some anomalous Ferns the ring is absent, and the 

 dehiscence takes place by a transverse rupture ; almost 

 all have the capsule unilocular ; but in Myriotheca it is 

 divided into several cells. 



From this cavity there proceeds, at dehiscence, a small 

 cloud of powder, which is composed of seeds or spores ; 



