TRANSACTIONS OF SECTION E. 533 
they dwell, both in character and beliefs. Magic is the dominant note of their 
lives. Ancestor-worship, Nature jujus, secret societies, and ceremonies for en- 
suring protection against witchcraft blend together in one complicated ritual. 
Yet traces still remain to show that these forest folk once lived in open country, 
bounded by wide horizons, like the present-day dwellers in the northern grass- 
lands. 
TUESDAY, SEPTEMBER 10. 
The following Papers were read :— 
1. Exploration in the Sonora Desert of Mexico. 
By I. N. Dracopou, F.R.G.S. 
The Sonora Desert is that part of Mexico which is bounded on the north by 
the International boundary-line, on the west by the Colorado River, on the east 
by the 111th meridian of west longitude, and which extends south to the head 
of the Gulf of California and along its coast as far as the 29th parallel of 
latitude. This large tract of country is singularly little known, though it con- 
tains much that is of great interest, both scientifically and commercially. Rising 
in the north-east to a height of 2,000 to 3,000 feet, and more in Southern Arizona, 
the country slopes gradually and, to the traveller, imperceptibly, towards the 
south-west till the coast is reached; and this great plain is characterised by a 
series of isolated mountain ranges, rising abruptly to an average height of 
4,000 feet and more, and from five to thirty miles in length. They usually run 
in the same general direction, south-east to north-west, thus dividing the 
country roughly into a series of broad and sandy valleys. The mountains, whose 
geological formation is chiefly volcanic and granite, are rugged in the extreme, 
with little vegetation as a rule, save cacti, but are highly mineralised, and 
traces of gold and copper are common in many parts. Round and to the north- 
west of Adair Bay is a broad belt of sand-dunes, at some points twenty miles in 
breadth, and the flora and some of the animals found therein are very local in 
character and are not seen elsewhere. The valleys contain in abundance trees 
—of which the most common are mesquito (Prosopis velutina) and paloverde 
(Parkinsonia torreyana)—shrubs and cacti. The appearance of the country is 
deceptive and would lead one to suppose that there was water in abundance, 
but the contrary is the case. Water is never plentiful, and in the majority of 
cases 1s von-existent, though there are indications that point to an abundant 
underground flow. The annual precipitation is about three inches, which falls 
during the months of July and August, at which time also the heat is greatest. 
As in all dry countries where evaporation is rapid, the daily range of tempera- 
ture is very great, there being often a difference of from 40° to 50° F. between the 
maximum and minimum; 120° in the shade is not at all uncommon in the day- 
time. 
The flora of this region has been wonderfully endowed by Nature with 
means for obtaining and storing water, and its study therefore cannot fail to 
interest the traveller. The country is remarkable for the great number and 
variety of its cacti, which form the main source of food to the wild animals and 
also to the Indians. The latter value them very highly, and once each spring 
hold a festival in their honour before setting out to gather their fruit. 
Southern Arizona and Northern Sonora are inhabited by the Papago Indians. 
They are a semi-nomadic tribe of Piman stock, and physically are a fine race. 
Being of a peaceful disposition they have not been much molested, but the 
coming of civilisation in the last twenty years has not proved an unmixed 
blessing, for it has brought to them, as to the Yuma Indians, the scourge of 
consumption and other terrible diseases unknown to them before. They have 
adopted the clothing of the Mexicans, but otherwise they remain little affected 
by the coming of the white man, and they still cling tenaciously for the most 
part to their religion and its many interesting customs. There are many traces 
of ancient civilisation in the Papago country, and other indications which tend 
to show that they are not indigenous to the country. Loe 
