Among the invertebrates special mention may be made of the great ailanthus silk-moth (_Attacus cynthia_) of northern China and Japan, and also of its Manchurian relative _A. pernyi_; while it may be added that the domesticated "silkworm" (_Bombyx mori_) is generally believed to be of Chinese origin, although this is not certain. Very characteristic of China is the abundance of handsomely coloured swallow-tailed butterflies of the family _Papilionidae_. The Chinese kermes (_Coccus sinensis_) is also worth mention, on account of it yielding wax. As regards land and freshwater snails, China exhibits a marked similarity to Siam and India; the two groups in which the Chinese province displays decided peculiarities of its own being _Helix_ (in the wider sense) and _Clausilia_. There are, for instance, nearly half a score of subgenera of _Helix_ whose headquarters are Chinese, while among these, forms with sinistral shells are relatively common. The genus _Clausilia_ is remarkable on account of attaining a second centre of development in China, where its finest species, referable to several subgenera, occur. Carnivorous molluscs include a peculiar slug (_Rathouisia_) and the shelled genera _Ennea_ and _Streptaxis_. In the western provinces species of _Buliminus_ are abundant, and in the operculate group _Heudeia_ forms a peculiar type akin to _Helicina_, but with internal foldings to the shell.
Lastly, it has to be mentioned that the waters of the Yangtsze-kiang are inhabited by a small jelly-fish, or medusa (_Limnocodium kawaii_), near akin to _L. sowerbii_, which was discovered in the hot-house tanks in the Botanical Gardens in the Regent's Park, London, but whose real home is probably the Amazon. (R. L.*)
The vegetation of China is extremely rich, no fewer than 9000 species of flowering plants having been already enumerated, of which nearly a half are endemic or not known to occur elsewhere. Whole provinces are as yet only partially explored; and the total flora is estimated to comprise ultimately 12,000 species. China is the continuation eastward of the great Himalayan mass, numerous chains of mountains running irregularly to the sea-board. Thousands of deep narrow valleys form isolated areas, where peculiar species have been evolved. Though the greater part of the country has long ago been cleared of its primeval forest and submitted to agriculture, there still remain some extensive forests and countless small woods in which the original flora is well preserved. Towards the north the vegetation is palaearctic, and differs little in its composition from that of Germany, Russia and Siberia. The flora of the western and central provinces is closely allied to that of the Himalayas and of Japan; while towards the south this element mingles with species derived from Indo-China, Burma and the plain of Hindostan. Above a certain elevation, decreasing with the latitude, but approximately 6000 ft. in the Yangtsze basin, there exist in districts remote from the traffic of the great rivers, extensive forests of conifers, like those of Central Europe in character, but with different species of silver fir, larch, spruce and Cembran pine. Below this altitude the woods are composed of deciduous and evergreen broad-leafed trees and shrubs, mingled together in a profusion of species. Pure broad-leafed forests of one or two species are rare, though small woods of oak, of alder and of birch are occasionally seen. There is nothing comparable to the extensive beech forests of Europe, the two species of Chinese beech being sporadic and rare trees. The heaths, _Calluna_ and _Erica_, which cover great tracts of barren sandy land in Europe, are absent from China, where the Ericaceous vegetation is made up of numerous species of _Rhododendron_, which often cover vast areas on the mountain slopes. Pine forests occur at low levels, but are always small in extent.