Dec, 1911.] The Classification of Plants, VII. 



Lll 



to normal organs it is not necessary to give much weight to such 

 results. In the higher plants vestiges are exceedingly abundant 

 and give a plain index to the course of phylogenetic development. 

 Derivations or supposed relationships are also frequently based 

 on assumptions from isolated morphological peculiarities which 

 can be explained equally well on other assumptions that will not 

 require the complete re-creation of the species from its supposed 



ancestor. 



The basis of a modern taxonomy must at all events include the 



following principles : 



1. The comparative study of the organography and anatomy 

 of plants, proceeding from the simple to the more complex. 



2. The definite recognition of primordia and transformations 

 on the one hand and of vestiges on the other. 



3. A study of incepts, embryological developments and 



juvenile forms. 



4. The investigation of lines of degeneration and special- 

 ization, in both low and high types, leading from complex to simple 



structures. 



5. The segregation of the units into genetically or phylogenet- 



ically related groups. 



6. The arrangement of the branches thus segregated into 

 series extending from the lowest and least differentiated to the 

 most highly specialized. 



7. In a word, the whole scheme of classification must show 

 the result which has come about through progressive evolution, 

 segregation, degredation, and specialization. 



In the sixth article of this series of papers, an arrangement 

 of the orders and families of Anthophyta found in the North- 

 eastern United States was given. Since then the scheme has 

 undergone some slight change in the writer's hands. It is be- 

 lieved that after this no important changes need be made foi^ 

 some time except perhaps the transfer of a few families after a 

 wider knowledge of them is gained. The changes are as follows :; 



Transfer the Limnanthaceae to the Geraniales following the 

 Oxalidaceae. 



Interchange the subfamilies Melanthatae and Liliatae, placing 

 the latter as the lowest group of the Liliaceae. 



Divide the Hydrangeaceae into two subfamilies, Philadel- 

 phatae and Hydrangeatae. 



Following the order, Saxifragales, insert the order Thyme- 

 leales including in sequence the families, Lythraceae, Thyme- 

 leaceae, Elaeagnaceae. 



A preliminary synopsis is now given of the subclasses and 

 orders of the Anthophyta. It is hoped that this may present a 

 better view of the phyletic classification as applied to the higher 

 plants and stimulate to further study. 



