REVIEWS. 35 
twin brothers under the same laws; and with the same treatment 
at nature’s hands, and stand to-day not rivals, but complements 
of each other. We do not find those strong contrasts in their 
physical and biological features, that we do in the opposing lands 
of Asia and Australia, where two continents almost join hands, 
and yet are most strangely opposed. 
For instance, Professor Hartt, seconded by the decision of Dr. 
Sterry Hunt, finds that the fundamental gneiss rocks of Brazil are 
the exact repetition of the Laurentian rocks of Labrador, Canada 
and the Adirondacks. The gold bearing rocks of the province of 
Minas, of probable Lower Silurian age repeat (oddly enough even 
to their geographical names) the characters of the auriferous strata 
lying about the basin of Minas in Nova Scotia. “The coal basins 
lie just south of the tropics, but within the range of the palm, 
and they are a coast formation, corresponding in this respect to 
the coal basins of Acadia, Massachusetts and Rhode Island.” To 
continue the wonderful parallelism, at a later chapter in the geo- 
logical history of Brazil, the Triassic Period, were deposited rocks 
agreeing precisely in physical characters with the New Red sand- 
stones of the Connecticut valley. The Cretaceous rocks embrace 
species of Ammonites considered by Prof. A. Hyatt as identical 
with Texan forms, which flourished on both sides of the Andes- 
Rocky Mountain chain, and lived in a sea which covered Brazil, 
Peru, and Texas alike, before the appearance of the Isthmus of 
Panama. The reptilian remains examined by Professor O. C. 
Marsh indicate crocodiles and gavials and others of the same 
genera as those found in the marls of New Jersey. The Tertiary 
clays and sands are less like those of other lands, so far as re- 
gards their fossils, the types being more specialized, ushering in 
the present tropical life of Brazil. 
The close analogy to the geological history of our northern 
continent, is, in the author’s view, farther carried out by Agassiz’s 
supposition of a continental Brazilian glacier. Here geologists 
differ, and most of them dissent from such a startling view. Pro- 
fessors Agassiz and Hartt do not know otherwise how to account 
for the presence of their “ unstratified” ‘‘ drift” clays and sands, 
often gold bearing, which are spread over the whole coast area 
from Rio to Pernambuco, and “in the valley of the Amazonas 
westward to the confines of Peru.” Geologists will more’ gener- 
ally credit the truth of the theory of the glacial origin of this thin 
