222 VEGETABLE ORGANOGRAPHY. 



A second difficulty which also contributes to cast 

 doubt upon the structure of these plants is, that several 

 of them appear furnished at the same time with both 

 modes of reproduction ; thus, several Mosses and Hepa- 

 ticae present both reproductive bodies, which, proceeding 

 from a fecundating apparatus, must be considered as 

 seeds, and others which seem to be true bulbs. If the 

 distinction between these two classes of bodies is so dif- 

 ficult in certain phanerogamous plants, we can compre- 

 hend how the difficulty must go on increasing here, 

 seeing the smallness of the organs, and the almost 

 impossibility of applying the laws of analogy. 



In fact, that which is most remarkable among Crypto- 

 gamous plants is, that the families of this class compared 

 together differ much more than the phanerogamous 

 families, and that the most nearly related present diver- 

 sities which would seem to declare a totally different 

 nature ; the laws of symmetry, which have so powerfully 

 aided us in discovering the true nature of the organs of 

 phanerogamous plants, can only be applied here in rare 

 and uncertain cases; this obliges us to study each family 

 in particular, without being able to derive from this ex- 

 amination any general laws for the entire class. 



All Cryptogamas are furnished with bodies which 

 serve to reproduce the species in the same manner as 

 seeds. The name of Spores has been given to them, a 

 term which ought to be considered as provisional ; for, 

 when it shall have been proved that these bodies have 

 been fecundated, we must call them seeds, and if it be 

 demonstrated that they are not fecundated, they would 

 take the name of bulbs. 



In most Cryptogamous plants, perhaps in all, the 

 spores are contained in a vesicle, or membranous cap- 

 sule, to which the name of Sporangium is often given ; 

 this organization is met with from the Ferns to the 



