CLASSIFICATION OF VASCULAR PLANTS 67 



ledons and monocotyledons. Similarly, in the Lycopsida, the 

 names of orders and families are practically fixed. The basis, 

 at least, is agreed upon. It must be noted, however, that the 

 orders in Lycopsida are very much more distinct from one 

 another than are the orders of dicots and monocots. The ter- 

 mination -ales is consistently used within each great group, but 

 is not used consistently when the two great groups are com- 

 pared. This is due to the one group being small and nearing 

 extinction, and the other being large and aggressive. The incon- 

 sistency is not objectionable, and is almost unavoidable. 



It seems necessary, for the sake of uniformity to adopt the 

 sub-ordinal names Isosporineae and Heterosporineae in place of 

 the more common Isosporeae or Isosporae and Heterosporeae, 

 both in lycopods and ferns. 



The ordinal grouping of ferns presents a somewhat difficult 

 problem. The second and third groups of Pteropsida are named 

 Gymnospermae and Angiospermae, each group being divided 

 into orders with names ending in -ales. The first or fern group 

 of pteropsidans therefore cannot properly be called Filicales. 

 But this is the term used by Gray's Manual, and by Jeffrey 

 throughout his Anatomy of Woody Plants. Engler recognizes 

 in the fern alliance three orders: Filicales leptosporangiatae, 

 Marattiales, and Ophioglossales. Coulter, in the Chicago text 

 book, recognizes only Ophioglossales and Filicales. Now the 

 usage of the Harvard systematists may be explained on the basis 

 of a group consisting of but one order, viz. Filicales, including 

 all the families from Ophioglossaceae to Salviniaceae. Even in 

 this case there is need for another term to stand co-ordinate 

 with Angiospermae and Gymnospermae. This term might be 

 Filices. For the sake of euphony, however, we have proposed 

 the name Aspermae for this group. The term also signifies the 

 real distinguishing character on which the divisions of Pteropsida 

 are based — in this case, the absence of seeds. The " alpha 

 privative" occurs also in the term Atracheata, and in many 

 other modern scientific terms; it is in good repute. The Asper- 

 mae may then include but one order, Filicales, if desired, in which 

 case Aspermae is practically synonymous with Filicales. Or, 





*r\i, 



