OKDEES OF LDSTN^US. 



21 



Fig. 10. 



The name of the 21st class is a compound of two Greek 

 words, CRYPTO and ga^iia, signifying a concealed union. 



Natural Families. 



21. Crypto-gamia, 



Stamens and Pistils invisible, or too small 

 to be seen with, the naked eye. 



Lichens, 



The number of classes as arranged by Linnjeus, "was twenty-four. Two of them, 

 Poly-adelphia (many brotherlioods), which was the eighteenth class ; and Poly- 

 gamia (many unions), the twenty-third class, are now, by many botanists, rejected 

 as unnecessary. The eleventh class, Dodecandria, which included plants whose 

 flowers contain from twelve to twenty stamens, has been more recently omitted. 

 The plants which were included in these three classes, have by most botanists been 

 distributed among the other classes. 



The Orders of LinncBus. 

 21. Tlie ORDERS of the first twelve classes are founded upon 

 the number of Pistils ; they are named by prefixing Gre^k nu- 

 merals to the word, gynl^, signify ing j^^^^-j^*^. 



Orders found in the 

 first twelve classes. 



1 13. Poly-gynia, over ten pistils. 



The classes vary as to the number of orders which they con- 

 tain. The orders of the 13th class, Didynamia, are but two. 



1. GYMNOSPERivnA. Fi'om gy:mnos, signifying naked, and 



Seeds usually four, lying in the SPERMIA, signifying sccd, implying that 



'^^^^■^- the seeds are not covered by a seed-vessel. 



What does Cryptogamia signify ?— Classes omitted. , 21. Orders of the first twelve classes, on what 

 founded?— How are the orders named ?— Orders of the ^^ss Didynamia. 



