252 Aspects of Ecology. 
Of the lesser sub-divisions of a formation, we are not familiar, 
in nature, with the society and the community as distinct from the 
association (consocies), hut we refrain from expressing any opinion 
without further study in the field. The family is clearly a natural 
unit; it is the group composed of parent and obviously derived 
offspring. 
The sections on investigation, classification and relationship of 
formations are extremely good, and so is the final one on “ experi¬ 
mental vegetation.” 
On the whole the fourth chapter, which we have reviewed at 
considerable length, contains, in our opinion, by far the most 
important contribution to the science of vegetation that has been 
made for many years. Though the points to which exception is 
taken naturally hulk largely in a critical review, they are few indeed 
compared with the whole extent of the chapter. This thorough 
careful and logical exposition of a difficult and little understood 
subject is worthy of all praise and is so largely original as to lay 
all ecologists under a heavy debt of obligation to Dr. Clements. 
Nomenclature. 
The question of nomenclature we have left till the last. In 
1902 Dr. Clements published in Engler’s falnbuchcv a “System of 
Nomenclature for Phytogeography,” which consisted of a number 
of formal rules (including a law of priority) and a formidable series 
of formation-names derived from Greek with a uniform termination, 
etc. This system had the disadvantage of being published accom¬ 
panied by a rather hostile note from Professor Engler, objecting to 
a law of priority, to the abolition of vernacular names, and depre¬ 
cating too great “ Schematismus ” on the ground that it would 
frighten people away from the subject* In the present work Dr. 
Clements carries his scheme yet further and embodies it in a 
glossary at the end of the volume. It is impossible to give any 
account of the system within reasonable limits of space, but we 
cannot help feeling that it does carry “Schematism ” to altogether 
impracticable lengths. We quite admit that the average human 
mind never gives a logical and consistent scheme of this kind a 
really fair consideration. It is altogether averse from having a new 
language suddenly created and thrust upon it, however suitable the 
language may be. For this very reason Dr. Clements’ effort is hope¬ 
less, precisely because it runs directly counter to an almost universal 
and overwhelming prejudice. At the same time we cannot think 
that a scheme of the kind is so necessary to avoid confusion as he 
