GEOAEAPHICAL DISTRIBUTION.
t h e circumpolar species are confined to the American section of tHe Circumpolar province;
t h e endemic factor thus becomes or 75-i per cent.—evidently a less natural result
tlian f^, or 87-5 per cent., the result in the table. If the Kurile-Kamstchatdale species
b e added to the Japanese, a total of 12 with an endemic factor of or 56-9 per cent.,
is obtained—again a less natural result than the or 66-6 per cent-, of the table. If
t h e species that occur in Arctic Siberia are considered along with those of the natui-al
Siberio-Turkestan province, the total reached is 57, the total endemic 34. Tliis gives an
endemic factor of or 59-6 per cent —again, as compared with tlie or 65 per cent.,
of the table, a less natural result. Finally, if the Arctic European species are added to
those of the true Eui-opean province, the total is raised to 43 without making any
addition to the number of endemic species. 'J'his makes the endemic factor or 76'7
per cent.—most clearly a less natural result than that of table, which is f-^-, or 85 per
cent.
I t is not necessary to discuss each of the provinces in such detail. One other example
is suificient to show how this reasoning may be extended to all the areas and to indicate
the statistical tests that have in every case been applied. If the Caucasian species be
added to the European, the conjoint total becomes 55, the endemic total 45, or no
gain in numbers from the union. But the percentage for the whole area now becomes
81-8 in place of the 85-0 which it has been shown exists in the true European province.
If they be added to the Siberio-Tui-kestan species, the total becomes 65, the endemic
total 44, or only a gain uf one on the whole area.' This gives a percentage of 67-6 in
place of the percentage of 73-3 shown by the Caucasian province already. Finally, if
t h e y be added to the Himalayan species, a total of 116 with an endemic total of 101
results. This again causes no improvement over the whole area, but gives it a percentage
of 87-0 in place of the 89'1 abeady shown to exist in the Himalayan province.
Besides this brief review of the general distribution of the genus, it is necessary to
give a more detailed account of the distribution in the Himalayan province in which all
t h e species described in this paper are found. Three very natural divisions are recognisable
within it: —
The Himalayan division proper. —Th i s includes on the west the Hindu-Kush
and ends in the east at the valley through which the Sanpo passes to
reach the Brahmaputra. It extends from 68° E. Long, to 95° E. Long.,
passes insensibly into the tableland of Tibet to the north, and is abruptly
defined by the plains of India and the valley of Assam on the south. It
contains 61 species, 43, or 70"5 per cent., of which are endemic.^
T h e Indo-Chinese division.—This extends from the Brahmaputra on the west
to Hunan tju the east, or between 95° E. Long, and 110° E, Long., and
is somewhat abruptly separated from China Proper by the Yang-tse-kian«''
valley on the north, while it passes insensibly into the uplands of Assam
and Burma on the south. It contains 47 species, of which 35, or 74 4
per cent., are endemic.
• Even this gain of one is doubtful, for (c/. Maxim,, Msl. Biol, s, 120) it is not certain tliat the apeciea ic question
(P. aehillea/olia] esisls in botli regions.
'This division of tlio Himalayan proTincc ¡8 almost exactly equivalent to the Emodic or "Wallichian" rexioii of
Schow's system of Phytogeography.
HIMALAYAN DIVISIONS.
3 The South Indian division.-Small and isolated, this embraces Southern India
and Ceylon, and contains two species which are both endemic.'
The facts are shown more succinctly in tabular form :—
TABLE VII.— Pediculares.
DmsiON.
Tot«l number of Number of species PoroentiLge ondemic.
True Himalayan: Emodic (of Scliow)
61 43 70-5
Indo-Chinese 47 35 74-4 '
South Indian 2 2 100-
The EMODIC division of the Himalayan province admits of convenient subdivision at
t h e valley of the Karnalli in Nepal into an eastern and a western half. This river,
whose course almost exactly coincides with 81-5° E. Long, (a Hne midway between the
eastern and western limits of the division), takes rise from the southern aspect of the
ridge that parts the inner Himalayan waters that flow west to the Sutlej and Indus fron.
those that flow east to the Sanpo and Brahmaputra. The western half contains 23 species,
of which 7, or 30'4 per cent., are endemic. It contains, however, 3 others that extend
f r om Persia, Turkestan or Tibet, but do not reach the eastern half, so that as against
t h e latter the western contains 10, or 43-5 per cent., of peculiar species. The eastern
half is twice as rich, yielding 49 species, of which 32, or 65-3 per cent., are endemic.
There are 6 others that extend from Tibet or Indo-China without reaching the western
half so that as against the western the eastern half contains 38, or 77'5 per cent., of
peculiar species. No such subdivision of the Indo-Chinese division is yet evident, although,
a s will presently appear, certain districts are distinctly discernible in it; nor is there any
subdivision possible in the South Indian division, the most remarkable feature of which
is that its species show greater affinities to Indo-Chinese than to Emodi c (truly Himalayan)
I n considering now the evidence as affecting the Himalayan districts, it must be
recollected that too little is really known of Himalayan botany to admit of other than
merely approximate results being stated. For while the Western Himalaya has, except
for a limited area (Kafiristan) near the Indus, been fairiy thoroughly investigated, the
Eastern Himalaya, except for a very small section near the centre (Sikkim-Chumbi), is still
unexplored.
The Trans-Indus' district comprises the Hindu-Kush and Karakorara (Mustagh) ranges
with the highlands of Afghanistan. It is physiographically united to the Panjab Himalaya
on the south-east, to the Kuen-lun (Chinese) on the east, to the Tianshan (Siberio-
Turkestan) on the north, and much less distinctly to the Persian highlands ou the west.
' It is necessary to point out hero that in admitting this South Indian Division within tl.e HLSTILATIN PBOTIMCE, the
canon that regulates the rccognitiou of -proTiiices from staiisiica is violated. The aDuexatiou of the Andean Division
to the AUBBICAN PBOVINOB is another instance of ihe same violation. It is indeed extremely probable that both South
India and tJie Northern Andes ore entitled to actual provincial rank, but the number of species they contain (two in the
ii)'st ease one in the second) is so small that it is more convenient to treat them along with the nearest adjacent
provinces! only ealUng attention in passing to the fact that the annexation is an intentional divergence from a rule that
has everyvrhei'c else been rigidly observed.
»Iraus-Indus from the Indian (not Enropean) poiat of view.
ANN. ROX, BOT. GAUD. CALCUTTA. YOL. III.