232 VEGETABLE ORGANOGRAPHY. 



these are little corpuscules, usually round, and reddish- 

 brown ; when sprinkled upon a sponge or moist earth we 

 see them evidently germinate, and reproduce the species 

 which gave birth to them. 



The seed or spore produces laterally a green body, at 

 first nearly cylindrical, but which afterwards expands 

 into a foliaceous limb, devoid of nerves, very similar to 

 those of certain Hepaticae, and which may be considered 

 as the cotyledon ; it sometimes becomes lobed at the 

 apex, sometimes it surrounds the base of the plant, so 

 that the following fronds appear to proceed from its 

 centre. It frequently shoots out radicles, either from 

 its margin or lower surface, and sooner or later is 

 destroyed, as is the case with the cotyledons of phanero- 

 gamous plants. It only remains, for the complete assi- 

 milation of these organs with cotyledons, to be assured 

 whether the foliaceous parts proceed from an integument, 

 or whether they are a simple prolongation of the globule. 

 The extreme minuteness of this body has not as yet 

 permitted this to be accurately observed, but the ana- 

 logy of this germination with that of Mosses, in which 

 Hedwig asserts that he has seen the rupture of the inte- 

 gument, ought to make us believe that it will also be 

 observed in Ferns. 



There are ferns which are called viviparous, because 

 young individuals are seen to arise from the margins of 

 their leaves, or from the centre of their clusters of fruc- 

 tifications. This phenomenon may be compared, either 

 to the development of embryos in Bryophyllum, or to 

 the germination in the pericarp which is observed in 

 certain species of Cuscuta. The Ferns in which this 

 takes place are Darea, Asplenium bulbiferum, A. ramosum, 

 Cyathea bulbifera, &c. 



