984 The American Naturadist. [November, 
ting this fact, then, such a floral covering could be well comprehended 
only after the exhaustive study-of the formations of the entire vegeta- 
tion region. Had this been done for the present contribution, many 
of the so-called formations would have been referred to the real forma- 
tions of which they are immature or incomplete expressions. Asa 
concrete illustration, all of what Professor MacMillan terms surf-bar- 
rier formations are merely isolated facies and patches of certain water- 
plant formations common throughout the Allegheny and Prairie prov- 
inces, 
In analysing too carefully, the author has noted everything distin- 
guishable as a formation, a method which serves very well for the mere 
cataloguing of phytogeographical phenomena, but is one scarcely to be 
commended as affording a basis for work of much value. Upon many 
such points, one not familiar with the country studied is incapable of 
passing judgment, but, in some instances, the mistakes are apparent 
even to one not conversant with the particular floral covering. Front- 
strand, mid-strand and back-strand represent merely a more or less 
radially biologically symmetrical formation, the nucleus of which is 
found in the back-strand, from which the formation “shades out” to- 
ward the lake with accustomed zonation. As for strand pools, the 
three sorts are merely developmental aspects of one formation. The 
formation is best represented by the back-strand pool, which is simply 
the ultimate expression of the water plant formation represented in its 
earlier stages by mid strand and front-strand pools. Dune pools are 
likewise to be referred to the same formation. Soil shore formations 
are not at all peculiar to the Lake of the Woods; they are aspects of 
formations which occur over a large portion of the continent. Talus 
formations are such only in rare instances ; they are usually incipient 
formations of very various types. It is perhaps unnecessary to point 
out further instances of such incorrect analysis. It only remains to re- 
mark the similarity between the many lists of species of different for- 
mations,and to call attention to the large number of meaningless ruderal 
and subruderal plants contained in them. Formational statistics to be 
of value must be arranged with reference to facies, principal species, 
secondary species, etc., and not in bald lists. 
—Roscoe Pounn, 
Freperic E. CLEMENTS. 
