,34 EXPLANATION OF THE CLASSES 



In the twenty-third class of Linnaeus, Polygamia, 

 now generally abolished as inconvenient in practice, and 

 incorporated with the preceding class Dicecia, there 

 are complete and incomplete flowers distributed on 

 two or three different individuals of the same spe- 

 cies. 



The last, or twenty-fourth class of this system, call- 

 ed Cryptogamia, from the obscurity of the parts of 

 fructification, merits almost the distinction of a sepa- 

 rate kingdom ; to it belong the Ferns, Mosses, Li- 

 chens, Seaweeds, and Fungusses. In all these, 

 though seed or spora be produced, of extreme minute- 

 ness, no distinct corolla, stamens, nor pistils are dis- 

 coverable, and the fruit itself is so inconspicuous as to 

 be a mere object for the exercise of the microscope. 

 In this tribe, generation appears almost spontaneous, 

 as in the Mould and Mucor, which show themselves 

 readily wherever there is moisture, and in the absence 

 of light so necessary to all other vegetables. Yet 

 even in these, the most simple of organized bodies, 

 appropriate receptacles are provided for the spores or 

 seminal germs, proving the existence of the universal 

 law of nature, that without a parent mediate or imme- 

 diate,* neither animal nor vegetable, in whatever part 

 of the scale of existence they are found, can possibly 

 have a being. 



* In these, as in all other plants, there are two modes of origin ; 

 one from the seed consequent on generation, and giving place to 

 variety ; the other soboliferous, individuals protruded as buds or off- 

 sets, and, when separated from the parent producing other perfect 

 plants, but possessed of all the qualities of the individual parent. 



