34 PRINCIPLES OF CLASSIFICATION. 



of their economy from those which have only two, 

 and are therefore comprehended under the same 

 denomination. 



90. Some Plants, especially those with anomalous or 

 obscure fructification, have been judged Acotyle- 

 dones, or destitute of a Cotyledon. The idea and 

 the term are partly founded in error. Of some 

 which have been thus considered, nothing is cor- 

 rectly known of the structure or germination of their 

 Seeds, as Fungi, and Submersed Algce (Fuel, Con- 

 ferva, &c.), nor has much been ascertained relative 

 to the Hepaticce, or the Lichenes. We know that 

 their Embryo is of the most simple kind, without 

 appearance of Cotyledons or Albumen, so that they 

 appear to differ from the Monocotyledones (88) 

 chiefly in the want of a separate Albumen, that nu- 

 tritious matter being probably lodged in the sub- 

 stance of the Embryo, as it is in the Cotyledons of 

 many of the Dicotyledones (62 : 3). But this is 

 conjectural. Muscl, Mosses, (77) properly consi- 

 dered, appear to agree with Hepatlca, to which 

 they are otherwise very closely allied, in having a 

 simple Embryo, without either separate Cotyledons 

 or Albumen. But they subsequently produce a pe- 

 culiar accessory organ, consisting of several branch- 

 ed and jointed fibres, springing upwards or laterally, 

 from the crown of the Root (7), and very distinct 

 from its radicles. These fibres are taken by Hed- ' 

 wig for Cotyledons, which from their late forma- 



