384 ON THE ETHNOGRAPHY AND PHILOLOGY OF THE 
surrounded by a border of tall flags and rushes, and in the autumn covered with myriads 
of wild fowl. A few small springs are seen occasionally, but most of them have a mineral 
taste, and possess active cathartic properties. 
Notwithstanding the dull and dreary appearance always presented by naked and exten- 
sive plains, there are no places that could properly be termed deserts, though there are some 
marshes, pools, and swamps, which, however, are not very near together, or of a nature to 
present any formidable obstruction to travel, neither do they seem to affect the health of the 
natives, any farther than being the breeding-place of hosts of mosquitoes, which are very 
annoying to man and beast. 
The principal hindrance to foot travellers in this district, is the great abundance of a 
few species of Cacti, or as they are usually called, “prickly pears,” some of which are 
armed with long, sharp, barbed spines, and readily pierce the moccasined feet of the In- 
dian or voyageur. ‘The dogs, also, used by the Indians for carrying burdens on the plains, 
suffer severely from these spines, though the older and more experienced have the faculty 
of perceiving and avoiding them even while running. ‘The principal varieties known in 
this region are Opuntia Missouriensis and O. fragilis, both species of which cover thou- 
sands of acres over the West. ‘The smaller and most annoying form is the O. fragilis, 
the joints of which separate very readily, and adhere by the spines to the legs of horses or 
the clothes of travellers, and owing to the barbed character of the thorns, produce often 
quite serious and painful results. 
The climate in this latitude is pure and dry, and perhaps the healthiest in the world. 
In the months of April, May, and to the middle of June, when east winds prevail, much 
rain falls, but during the rest of the summer and autumn, the weather is dry and mode- 
rately warm, there being only a short period in July and August of intense heat. There 
are not unfrequently severe thunderstorms during the hot season, accompanied by rain or 
hail, which in a few hours swell the small streams so that they overflow their banks, but 
with the cessation of the rain, they fall as suddenly as they rise. ‘The Missouri and most 
of its tributaries inundate the neighboring valleys, when rain falls for ten or fifteen days 
in succession. ‘This usually happens in the month of June, when they are already nearly 
full of water from the snow melting near their heads. This is not, however, of very fre- 
quent occurrence. Strong gales of wind also come from the west and southwest in form 
of sudden gusts, prostrating numbers of trees along the banks of the Missouri, but these 
storms only last for a few moments, and are not common. ‘The summer season, being 
short, leaves vegetation but little time to decay, and the firing of the prairies, which 
happens more or less every year in different parts, burns up all the old grass, fallen timber, 
and underbrush along the river bottoms. Owing partly to these facts, partly to the very 
equable temperature, and the absence of excessive moisture, the air is pure and invigorating, 
