34 PRINCIPLES OF CLASSIFICATION. 



no particular 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 ot 

 their Seeds, as Fungi, and Submersed Algce (Fuci, 

 Conferva, &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 Monocotyle- 

 clones (88) chiefly in the want of a separate Albu- 

 men, that nutritious matter being probably lodged 

 in the substance of the Embryo, as it is in the 

 Cotyledons of many of the Dicotyledones (62 : 3). 

 But this is conjectural. Musci, Mosses, (77) 

 properly considered, appear to agree with Hepa- 

 ticce, to which they are otherwise very closely 

 allied, in having a simple Embryo, without either 

 separate Cotyledons or Albumen. But they sub- 

 sequently produce a peculiar accessory organ, 

 consisting of several branched 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 Hedwig for Cotyledons, 

 which from their late formation they can scarcely 



