86 Frazer on Int. Cong, of Geologists. 
middle and lower palajontological divisions. One of two con- 
clusions seems inevitable. Either sediments do not always re- 
cord changes in physical conditions, or a whole fauna may be 
blotted out and be succeeded by a totally different fauna with- 
out any change in the physical environment. One great factor 
in the extinction of species, as all biologists admit, is competi- 
tion with other species. It may be, therefore, that the long- 
winged spirifers, through some defect in organization and under 
the conditions existing in that particular locality, were unable 
to hold their own against an invasion of their territory by corals. 
While, however, the corals of the middle division of our section 
were flourishing in imdisputed possession of the region, the 
descendants of the long-winged spirifers that had been forced 
to migrate and establish themselves elsewhere, were undergoing 
modifications which fitted them better for the "irrepressible 
conflict;" and so, when the time is ripe, a hardier and more 
prolific variety, with shorter hinge and more robust form, de- 
scends upon the same region and occupies it, to the complete 
exclusion of the enemies of their long-winged ancestors. All 
this at least is conceivable ; and notwithstanding the absence of 
any record to that effect, it is also conceivable that the organic 
changes so plainly recorded in the Hamilton section of Ontario, 
may have been aided by mutations in the physical environment. 
A SHORT HISTORY OF THE ORIGIN AND ACTS OF THE 
INTERNATIONAL CONGRESS OF GEOLOGISTS, AND 
OF THE AMERICAN COMMITTEE DELEGATES TO IT. 
BY PERSIFOR FRAZEK. 
(Continued from the January number.) 
The report of the proceedings of the first Congress was pub- 
lished by the Imprimeri^ Nationale in i8So under the direction 
of M. Thirion, secretar}' of the Central Committee. It forms a 
volume of 313 pages and is illustrated by seven cuts in all. It 
probably can be obtained still through any large firm of book 
sellers but will doubtless be soon out of print. 
