526 The American Naturalist. [June, 
“ VI. The sub-stages can have but a regional value. (The commis- 
sion thinks that the International Congress has not to concern itself 
with the final divisions which have only a local value).” 
“ VII. The divisions of the same order ought to present as much 
equivalence as pessible from the point of view of the paleontological 
evolution which they represent.” 
“N. B. The commission recognizes that the geographical variations 
ought to be taken into serious consideration in the establishment of 
divisions of different orders; but on account of the frequently local 
character of the variations, and above all of the actual imperfection of 
our knowledge so far as relates to the old beaches, it thinks that the 
stratigraphical argument needs to be confirmed by the paleontological 
criterion.” 
At the Manchester meeting M. Hughes called attention to the nec- 
essity of discussing principles before the applications; on his motion 
the commission decided to ask the Congress to determine primarily the 
rules of stratigraphic terminology, such as the rules to follow in the 
historical and stratigraphical criticism, above all from the point of 
view of the law of priority. 
The commission concludes its report with the following sentence: 
“ It seems evident that it would considerably shorten the discussions 
if the Congress proceed in this way.” 
Unfortunately the Congress of London could not profit by the sen- 
sible ideas enunciated at Geneva and Manchester, and was obliged to 
continue its labors in the direction imposed by the session at Berlin. 
Similarly the questions put by the commission for unifying the nomen- 
clature were neglected at the Congresses of Washington and Ziirich. 
Consequently it would be desirable that the Congress of Russia return 
to the questions having an international character, and that the decis- 
ions of the commissions of Geneva and Manchester that we have just 
cited (to which could be added some general theses) should become the 
basis of the questions to discuss. 
The Committee on Organization of the Congress of St. Petersburg is 
of the opinion that before taking up the other questions, the Congress 
should decide primarily which of the two classifications it wishes to re- 
tain in the science, the artificial classification based solely on historical 
data, or the natural classification which bases itself as much on i 
general physico-geographical changes, common to the whole terrestrial 
globe, as on the faunal data, and not on the accidental limits of the 
different divisions called after the name of the region where they have 
been established for the first time. 
