y should be crawling among crystals of sulphate
of soda and lime! And what becomes of these worms when, during the
long summer, the surface is hardened into a solid layer of salt?

Flamingoes in considerable numbers inhabit this lake, and breed
here, throughout Patagonia, in Northern Chile, and at the Galapagos
Islands, I met with these birds wherever there were lakes of brine.
I saw them here wading about in search of food--probably for the
worms which burrow in the mud; and these latter probably feed on
infusoria or confervae. Thus we have a little living world within
itself, adapted to these inland lakes of brine. A minute
crustaceous animal (Cancer salinus) is said to live in countless
numbers in the brine-pans at Lymington: but only in those in which
the fluid has attained, from evaporation, considerable
strength--namely, about a quarter of a pound of salt to a pint of
water. (4/4. "Linnaean Transactions" volume 11 page 205. It is
remarkable how all the circumstances connected with the salt-lakes
in Siberia and Patagonia are similar. Siberia, like Patagonia,
appears to have been recently elevated above the waters of the sea.
In both countries the salt-lakes occupy shallow depressions in the
plains; in both the mud on the borders is black and fetid; beneath
the crust of common salt, sulphate of soda or of magnesia occurs,
imperfectly crystallised; and in both, the muddy sand is mixed with
lentils of gypsum. The Siberian salt-lakes are inhabited by small
crustaceous animals; and flamingoes ("Edinburgh New Philosical
Journal" January 1830) likewise frequent them. As these
circumstances, apparently so trifling, occur in two distant
continents, we may feel sure that they are the necessary results of
common causes.--See "Pallas's Travels" 1793 to 1794 pages 129 to
134.) Well may we affirm that every part of the world is habitable!
Whether lakes of brine, or those subterranean ones hidden beneath
volcanic mountains--warm mineral springs--the wide expanse and
depths of the ocean--the upper regions of the atmosphere, and even
the surface of perpetual snow--all support organic beings.

To the northward of the Rio Negro, between it and the inhabited
country near Buenos Ayres, the Spaniards have only one small
settlement, recently established at Bahia Blanca. The distance in a
straight line to Buenos Ayres is very nearly five hundred British
miles. The wandering tribes of horse Indians, which have always
occupied the greate