116 KANSAS CITY REVIEW OF SCIENCE. 
We have given this critique of the six maps examined, and the readej- will 
naturally ask what then? what has all this proved or developed? 
We have, we think, shown that the earliest explorations of the Pacific north- 
west coast, and of the Gulf of California, from 1533 until the middle of the 17th 
century or thereabout, proved that California was a large peninsula. That later 
in the 17th century it was then known and described first, we believe, by Janssen, 
a Hollander, as an island, and that by the middle of the i8th century it was again 
proved to be a peninsula. 
Within a third of a century surveys and explorations in California have 
proved beyond doubt that extending west of the Great Colorado from near Fort 
Yuma, a vast depression exists below the level of the Pacific Ocean. That east 
of the San Bernardino Range and running southeast is a vast arid basin, treeless 
and almost waterless, sixty feet or more below sea level, with the present exist- 
ing bed of a stream at its lower end leading to the Colorado and called "New 
River." This depressed area shows marks of the comparatively recent presence 
of water, and has been once completely submerged. Our theory is that since the 
early exploration of Ulloa and Alar^on, or even much later in time, this 
area of depressed land has been occupied by water, and that in Cabot's map the 
Maha-beyo is the present New River, now nearly dry. That Spanish explorations 
in the 17th century found this depressed area then covered with water, although 
land stretched westward from the Great Colorado to the then inland lake ; that 
this lake had been formed by the overflow of the Great Colorado, which after- 
ward became dry, its former communication with that stream being destroyed; a 
probable movement of elevation taking place, a few years exposure to the dry 
winds and intense heat of that region soon evaporating the overflowed area, and 
sufficing to render it what it really is, the dry bed of an evaporated fresh-water 
lake, in which a few estuary shells may have at one time of unusual height, crept 
up from the Gulf, when following the brackish waters mingling at the mouth of 
the Great Colorado. 
We certainly believe this was the origin of Janssen's Spanish Account, while 
the latitudes given on Cabot's map certainly place the head of the Gulf much 
farther north than in more recent maps. New River is also shown in Patavino's 
map. Nor is it unreasonable to believe that three and a half centuries since the 
Gulf extended to near the present Ft. Yuma. 
The American Naturalist iox June, 1883, and Science for May 25th, present 
their readers with abstracts of Dr. Edwin R. Heath's article in the April number 
of the Kansas City Review upon "Dialects of Bolivian Indians," as an import- 
ant and valuable contribution to geographical and ethnological literature. 
