The bulk of the Laos tribes are spread over the north-eastern valley of the Mekong, from 21° to 13° north latitude. This extensive region is a sort of _terra incognita_, reported to be thickly settled except along the regions contiguous to the Tonquin Mountains, where the villages are exposed to sudden raids from the wild tribes known as “inhabitants of the heights,” who sometimes strike hands with the Chinese refugees in making a foray over the border, carrying off the peasants as slaves and driving away cattle, with whatever in the shape of plunder can be moved. The caravans of pack-traders from Ssumao on the Yunnan frontier bring back large loads of the celebrated _so-called_ Puekr tea and cotton; whence it is inferred this plain must be fertile and extensively cultivated. Talā Sap (Sweet-water Lake), the great lake of Cambodia, forms a sort of back-water to the river Mekong, with which its lower end connects by the Udong. It belongs partly to Siam and partly to Cambodia. It is one of those sheets of water called in Bengal _jhéts_――viz. a shallow depression in an alluvial plain, retaining part of the annual overflow throughout the entire year, hence subject to great variations of extent and depth. In the dry season the average depth is four feet, and the highest floods entirely submerge even the forests on its banks. It takes about five days to traverse the lake when full. Extensive fishing-villages, erected on piles, stud the lake, reminding Mr. Thomson of “the pre-historic lake-dwellings of Switzerland.” The houses are above a bamboo platform common to the entire settlement and used for drying fish. This lake is an object of superstitious veneration to the natives, the fish furnishing them with the most important source of their livelihood. Enormous quantities are exported, dried or alive in cages, while immense supplies are furnished to Anamese villages to be boiled down into oil, thus giving lucrative employment to thousands. The small remnant of the ancient kingdom of Cambodia forms a rough parallelogram, consisting in large part of an alluvial plain lying athwart the Mekong, uncomfortably wedged in between Siam, Anam and the French delta, with a very short west coast-line. It would appear from Chinese annals that at an early period the Cambodians were an exceedingly warlike race, and that their authority extended over many of the Laos and even Siam. But for centuries Cambodian influence in Indo-China has been on the decline. It has little more than the name of an independent government at present, being under a joint protectorate of Siam and France, and tributary to both.