Se ae 
THE AUSTRALIAN NATURALIST. 59 
A new era seems probable in American politics, in 
which the governing power will be in the hands of trained 
men of the highest character. 
Passing, then, to the south-west, to Oklahoma and 
Western Texas, the origin of the prairies was discussed. 
They were shown to be not so much natural plant com- 
munities, but to have been artificially preserved by the 
practice of the Indians to fire the old grass every year to 
encourage new growth for their horses and the vast herds 
of buffalo, etc., upon which they lived. This herd, travel- 
ling north and south with the seasons, kept the pastures 
in good heart by periodical grazings and rests. To-day 
the northern prairies are farmland. To the south, the 
over-stocking which accompanied the white man has re- 
sulted in the loss of grass, and a serious depreciation in 
the grazing capacity of the land. Grass fires are no longer 
possible, and from the hilly and rougher country there is 
spreading on to the grazing land thickets of cacti, acacias 
and mesquite, which, though having a certain value, are 
not equal to the grasses they replace. 
In regard to the cacti, it is evident that the natural 
conditions which have controlled their distribution in the 
past, have been definite limits of cold and drought and 
grass fires. Insects, fungi, etc., have played a little part 
in checking them. ‘To-day, in the absence of grass fires, 
cacti are spreading within the climatic limits. 
Cacti are being increasingly used for stock forage in 
conjunction with cotton-seed meal, a highly concentrated 
food cheaply available. They are now being cultivated, 
particularly the spiny forms, which have several advan- 
tages over the less hardy spineless forms. 
Date growing has become an established industry in 
the hottest and driest districts of Arizona and California 
where water is available for irrigation, and is finding a 
use for land otherwise of little value. 
Reference was made to Mexico and the influence the 
early Spanish settlement has had upon California, par- 
ticularly in regard to the so-called mission style of archi- 
tecture and furniture. — 
Pictures were shown to illustrate the marvellous 
change which has been wrought in barren valleys by irri- 
gation. The beauty of some of the scenes in Southern Cali- 
fornia is hard to imagine. One may stand under giant 
Australian eucalypts and gaze across miles of orange groves, 
concealing cities in their greenery to the startling con- 
