NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
56
Scientific Memoirs by
uninhabited islands, as well as the inhabited. On the other hand, if man did not
settle on the archipelago on account of its coco-nut trees, it is difficult to conceive
what he went there for at all. The surface is not adequate nor are the conditions
favourable for cereal cultivation; and fishing is exactly the occupation that may
be said to be neglected by the Laccadive Islanders. It is true that they may not
always have neglected their opportunities of fishing; but the fact that in islands
where they are well-to-do the inhabitants now-a-days do not fish, taken in con
-junction with the evidence derived from the facts of coco-nut distribution else
-where, makes it almost certain that the coco-nut has reached the Laccadives in
-dependently of man's agency. Of the 17 cultivated species then, man has cer
- t a i n l y i n t r o d u c e d 1 5 , a n d p r o b a b l y 1 6 . B u t t h e s e d o n o t e x h a u s t t h e n u m b e r
of species intentionally introduced. Three others:—
Banyan,
Clitoria Ternatea.
Ixora coccinea,
are not only under cultivation at present, but cannot have their presence
well explained except by assuming that they have been intentionally introduced.
The Banyan is not, it is true, a very favourite tree with Musalmans; still, there is
a certain amount of sentiment in connection with it which even the good
Musalman does not readily overcome, and which must be unusually strong in a
Sub-Hindoo Musalman population, like that of the Laccadives. The Ixora
grows at the edges of the small patches of cultivation ; and, though it may have
been introduced only on account of its ornamental flowers, it must be borne in
mind that many natives of India ascribe, and probably with justice, valuable
anti-dysenteric qualities to the bark of its roots. It should be noticed too that
the Laccadive plant is not Ixora coccinea proper, but a form of the species
which Dr. Roxburgh considered specifically distinct, and to which he gave
the name I. Bandhuca, and it is to this form that medicinal virtues are especially
attributed. The Clitoria is a very favourite creeper in all Indian gardens, and is
perhaps grown by the islanders only on account of the beauty of its flowers; it
has, however, a reputation for the cathartic properties of its roots and of its
seeds, those of the former being the more powerful.
Besides the castor-oil plant, however, there are 16 other species that it is
possible the islanders may have introduced intentionally. These are:—
The Poon-spar tree (Calophyllum).
The Portia tree (Thespesia).
Mucuna capitata.
Cæsalpinia Bonducella.
Morinda citrifolia.
Plumbago zeylanica.
Calotropis gigantea.
Cynanchum alatum.
Tylophora asthmatica.
I pomœa grandifiora.
Datura fastuosa.
Stachytarpheta indica.
Premna integrifolia.
Gloriosa superba.
Pandanu s odoratissimus.
Cynodon Dactylon (?)
58
Scientific Memoirs by
a wide-spread species that probably only occurs in India as a cultivated plant,
and is very generally planted throughout the Malay Archipelago, North Australia,
Polynesia and Africa,1 m a i n l y f o r t h e d y e - s t u f f y i e l d e d b y i t s r o o t s . B u t t h e
Laccadive plant is not true M. citrifolia,b u t t h a t v a r i e t y w h i c h D r . R o x b u r g h
considered a distinct species and named M. bracteata. This plant is confined
to India, Ceylon, and the Andamans, is perhaps oftener wild than cultivated,
and was, where Mr. Hume found it, certainly wild. Unless then it be assumed
that this plant has here escaped from cultivation, and that its cultivation has
been at the same time given up, the species must be looked on as an example of
a sea-introduced plant. Mr. Hemsley (" Challenger" Reports; Botany, Introd.,
p. 43) contends for an ocean-distribution for true M. citrifolia, and the evidence
from this variety certainly supports his view.
Plumbago zeylanica is a common plant in Indian Bard ens,and, besides being
grown for its appearance, is used in Indian domestic medicine in skin diseases.
It has therefore probably been introduced intentionally. At the same time it is a
plant that readily throws itself out of cultivation, and it may have reached the
Laccadives only as a weed.
Calotropis gigantea may have been intentionally introduced. Its milky
juice is medicinal, and it yields an excellent fibre used along the western coast
of India. At the same time it is a common road-side weed everywhere on the
mainland, and it may be as a weed that it has reached the islands, while there is
nothing to have prevented its seeds from having been brought from the mainland
by winds. Then both Cynanchum and Tylophora may have been introduced on
account of their juice, since they too are Milk-weeds; it is, however, far more pro
-bable that they have reached the islands with the assistance of wind.
The large-flowered Ipomœa may have been intentionally introduced, or more
probably perhaps, have arrived as a weed. At the same time the seeds of several
species of Ipomœa occur frequently in ocean-drifts, and some are characterized by
the readiness with which they become distributed by ocean-currents. To
strengthen this possibility we have here the fact that Mr. Humefound the species
in Betrapar, which is one of the uninhabited islands. On the whole then this
species is more probably sea-distributed, though the mere fact that it occurs
where there are no inhabitants does not render the evidence conclusive; since the
island is visited by the inhabitants of the other islands of the group, and since
it does not follow, because Betrapar has no permanent inhabitants now, that
this has been always the case.
The Datura may have been introduced purposely, for it is not infrequently
deliberately cultivated by evil-disposed people. It is, however, a common Indian
weed, and has probably been only unintentionally introduced.
1 Mr. Hemsley ("Challenger" Reports; Botany, vol. i, part iii, p. 109) gives America also.
Medical Officers of the Army of India.
59
Stachytarpheta indica is a common and favourite flower in Indian gardens,
and may have been intentionally introduced. But it is also (like Plumbago) a
plant that readily throws itself out of cultivation, and is nearly as likely to have
been unintentionally conveyed.
Premna integrifolia may possibly have been introduced because of its
medicinal properties. It has, however, more probably arrived independently of
man. Mr. Hume found it wild, and in dense thickets; it is a common tree on
Indian coasts; it is perfectly capable of distribution by ocean-currents (fruits
almost certainly belonging to this genus occur in various ocean-drifts); it is also
probably capable of dispersal by means of frugivorous birds, as seeds of appa
- r e n t l y s p e c i e s o f
P r e m n a
h a v e b e e n f o u n d i n t h e c r o p s o f s u c h .
On the other hand, Gloriosa is more likely to have been introduced; not
only is it a showy plant, but natives of India believe that its roots possess
powerful poisonous properties. It must be pointed out, however, that its seeds are
capable of dispersal by winds, though it may be doubted whether they are capable
of being carried so far as 130 miles, which is the distance of Anderut from the
mainland. But it was not being cultivated where it was gathered, nor was it in
cultivation elsewhere.
Pandanus odoratissimus may have been introduced because of its sweet
scent. But it is very general in the archipelago; it is not cultivated by the
islanders, and they do not make any use of it; species of Pandanus are amongst
the most usual of ocean-distributed plants elsewhere; and it may be held as
almost certain that it has been introduced by ocean-currents.
The grass that Mr. Hume took to be the common dubh-grass may have been
introduced purposely, since some of the islanders have a few cattle; but it is far
more likely, even if it was dubh, which it is extremely probable it was, to have
been introduced as a weed.
Whi l e , t he n, a l l 16 ma y ha ve be e n i nt e nt i ona l l y i nt r oduc e d by ma n, i t i s
more probable that 7 (Cœsalpinia, Morinda, Cynanchum, Tylophora, Ipomœa,
Premna and Pandanus) have arrived independently, and just possible that 5
others (Calophyllum, Thespesia, Mucuna, Calotropis and Gloriosa) may also
have arrived independently. The remaining 4 (Plumbago, Datura, Stachytar
-theta and Cynodon) have either been introduced intentionally or have been intro
-duced as weeds, and so certainly owe their presence in the islands to the agency
of man.
But, besides these four, there are 27 other species that are or may be weeds
of cultivation, and as such are extremely liable to be dispersed by man involun
-tarily. For all in the following list this is without doubt the principal means of
dispersion, and for the majority it is unquestionably the only possible means.
J2
60
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Some, however, for which other modes of distribution have been observed or
claimed require discussion in detail. The list is as follows:—
Cleome viscosa.
Sida humilis.
Abutilon indicum.
Cardiospermum Halicacabum.
Crotalaria verrucosa.
Vernonia cinerea.
Ageratum conyzoides.
Wedelia calendulacea.
Wedelia biflora.
Crepis acaulis.
Physalis minima.
Barleria Prionitis.
Barleria cristata.
Rungia parviflora.
Peristrophe bicalyculata.
Leucas aspera.
Bœrhaavia repens.
Aerua lanata.
Achyranthes aspera.
Euphorbia pilulifera.
Phyllanthus maderaspatensis.
Acalypha indica.
Op l i s me n u s c o mp o s i t u s .
S e t a r i a v e r t i c i l l a t a . A n d r o p o g o n c o n t o r t u s . A p l u d a a r i s t a t a . E l e u s i n e æ g y p t i a c a .
The species of Compositæ at once suggest the possibility of wind distribu
- t i o n . B u t t h r e e o f t h e m , t h e
A g e r a t u m
a n d b o t h t h e
W e d e l i a s ,
a r e n o t p r o v i d e d
with the feathery pappus favourable for wind-dispersal, and though Dr. Treub
has made it abundantly evident that certain Compositæ may have their fruits
wafted over 12—20 miles of intervening sea1, it remains true, as M. A.
DeCandolle has shown, that this is not very usual2, and it seems doubtful whether
the pappus of the Vernonia at all events is capable of supporting its fruit during
a flight of 130 miles. The pappus of Crepis is, however, long and silky; and
though its fruit is by no means so well adapted for aerial dispersion as the seeds
of the Milk-worts are, it must be recollected that wind-dispersion is just possible
for this species. Mr. Hemsley claims for Boerhaavia a dispersal by means of
ocean-currents 3 and, considering the nature of their seeds and the facts of their
distribution, the same dispersal may be claimed for Aerua and Achyranthes.
But the evidence is not altogether conclusive. All three were collected by Mr.
Hume on an island which is not inhabited; so far then the contention above stated
is supported. But their fruits have not been recognized in ocean-drifts; and
though this does not by any means preclude the possibility of their being pre
- s e n t , n o m o r e d o e s t h e i r e x i s t e n c e o n t h i s u n i n h a b i t e d i s l a n d p r e v e n t t h e m f r o m
having been possibly introduced by man. Two are cosmopolitan weeds of the
tropics; the third is widely spread in the tropics of the old world; all three are
species whose seeds or fruits would naturally be found in the notoriously dirty
grain sold in Indian bazars, and the Laccadive Islanders purchase their grain-
supply for the season in India where these weeds abound. Then, though
Betrapar is not inhabited, the people of other islands visit it to get its coco-nuts and
1 A n n . J a r d . B o t . B u i t e n z o r g , v o l . v i i , p . 2 1 9 .
2 G é o g r a p h i e B o t a n i q u e R a i s o n é e , p . 7 0 2 .
3 H e m s l e y ; " C h a l l e n g e r " R e p o r t s ; B o t a n y , V o l . i , p a r t i i i , p a g e 4 4 .
Medical Officers of the Army of India.
61
to collect birds' eggs. The presence of shelter-huts on the island indicates
that these visits are of some duration, and altogether the conditions necessary
to explain the presence of these three weeds without having recourse to the
hypothesis of ocean-dispersal are abundantly fulfilled.
The grasses too suggest at once the possibility of wind-distribution. But
none of those in the list are adapted (as an Imperata or a Saccharum would be)
for this method of distribution. Some species of Panicum have been supposed
to be distributed by the sea, but the Oplismenus and the Setaria, whose general
resemblance to the Panica suggests for them this possibility, are most distinctly
not coast plants on the mainland, and the hypothesis can hardly be applied to
them. The Apluda and the Andropogon are, however, both coast and inland
plants; for them therefore, though it is by no means probable, a sea-dispersal is
just possible. Then any, or all, of them may conceivably have been distributed by
marsh birds if their grains had happened to fall on the mud where these birds
were wading. But it is far more probable that all the grasses mentioned here
are, as Eleusine œgyptiaca certainly is, to be accounted for in the Laccadives as
weeds of cultivation.
Man then has almost certainly either intentionally or unintentionally intro
- d u c e d 4 3 s p e c i e s , o r 5 4 p e r c e n t . , o f L a c c a d i v e f l o r a . A t t h e s a m e t i m e i t i s
possible that he may have introduced as many as 63 species, or 78¾ per cent.
of the whole, while the probability is that man has introduced 56 species, or 70
per cent. of the whole flora. Conversely, the number of species that may have
been introduced otherwise than by human agency is 37, or 46 per cent, of the
f l o r a ; o n t h e o t h e r h a n d , t h e n u m b e r o f s p e c i e s w h o s e i n t r o d u c t i o n h a s a l m o s t
certainly been independent of man's agency is only 17, making 21¼ per cent. of
the flora; the number of species whose appearance is probably independent of
man is 24, or 30 per cent. of the flora.
Of the 17 species that have almost certainly not been introduced by man
the following five are inland plants:—
Vitis carnosa.
Herpestis Monniera.
Oldenlandia diffusa.
Nephrodium molle.
Nephrolepis tuberosa.
The introduction of Vitis carnosa is almost certainly due to the agency of
frugivorous birds, which have eaten its fruits on the mainland and deposited the
undigested seeds on the island where it occurs. Still it has to be remembered
that fruits belonging to this natural order have been found in ocean-drifts, 1
and that seeds of species whose fruits have been cast up by the sea have sub
- s e q u e n t l y g e r m i n a t e d .
2 B e s i d e s t h e w i l d v i n e , f r u g i v o r o u s b i r d s , a s h a s a l r e a d y
been said, may have introduced Premna; but, whereas for the vine the probabi-
1 Hemsley: " Challenger " Reports; Botany, vol. i, part iii, p. 290.
2 Lefroy: Bot. Bermuda, p. 61.
62
Scientific Memoirs by
lity of bird-introduction is greater, for Premna the probability is in favour of
introduction by the sea.
Herpestis and Oldenlandia are marsh plants with small seeds that might
easily be conveyed in pellets of mud attached to the feet of wading birds.
They clearly may owe their introduction to this agency, and are the only Lac
-cadive species for which this mode is the only conceivable one. But this agency
may possibly account for the introduction of some of the grasses as well, and
by no means improbably explains, at least in part, the distribution of one of the
sedges.
The spores of both ferns are almost certainly wind-introduced; the wind
probably also explains the presence of Cynanchum and Tylophora, not impro
-bably the presence of Crepis and Calotropis, and possibly, though this is less
likely, the presence of Gloriosa.
The other twelve are coast species, and have almost certainly been all intro
-duced by the sea. They are—
Suriana maritima.
Guettarda speciosa.
Launea pinnatifida.
Scævola Koenigii.
Tournefortia argentea.
Ipomœa biloba.
Hernandia peltata.
Euphorbia Atoto.
Cyperus arenarius.
Cyperus pennatus.
Spinifex squarrosus.
Lepturus repens.
One of them (Cyperus pennatus)o c c u r s o n m u d f l a t s i n t i d a l e s t u a r i e s , a s
well as on open shores, and may owe its distribution at least in part to the feet
of wading birds. For the others the distribution is clear. But there are
several species concerning which the evidence is hardly less doubtful. These
a r e —
Cæsalpinia Bonducella.
Morinda citrifolia.
Ipomœa grandiflora.
Premna integrifolia.
Pandanus odoratissimus.
Cocos nucifera.
But there are others still, all already alluded to and more or less exhaus
- t i v e l y d i s c u s s e d , f o r w h i c h a n o c e a n - d i s t r i b u t i o n i s q u i t e c o n c e i v a b l e . T h e y
are—
Calophyllum inophyllum.
Thespesia populnea.
Bœrhaavia repens.
Aerua lanata.
Achyranthes aspera.
Apluda aristata.
and there are a few others for which the possibility is so slight that they need
not be again mentioned.
The number and proportion of the species that have been certainly, or
possibly, or probably influenced in their introduction by the various agents of
distribution are more easily appreciated when shown in the form of a table—
Medical Officers of the Army of India.
63
TABLE I.—Modes of introduction of Laccadive Plants.
INTRODUCED BY
CERTAINLY.
POSSIBLY.
PROBABLY.
No. of Sp. Per cent. No. of Sp. Per cent. No. of Sp. Per cent.
Man
.
.
.
.
.
43
54 %
63
78¾%
56
70 %
The Sea
. . . .
1 1
13¾%
22
27½%
17
21¼%
Birds
.
.
.
.
.
2
2½%
5
6¼%
3
3¾%
Winds .
.
.
.
.
2
2½%
7
8¾%
4
5 %
The general distribution of the flora is, next to its means of introduction, the
feature of greatest interest. The majority of its constituent species, cultivated
and wild alike, are cosmopolitan in the tropics, while there is not a single species
that the flora does not share with the adjacent Indian mainland, and only five that
it does not share with Ceylon. Even Lepturus repens, for which the archipelago
is a new, but not an unexpected locality and which has not been hitherto in
-cluded in Indian lists, was collected by Mr. Hume at Vingorla Rocks near the
Goanese coast during the same voyage as that in which he obtained his
Laccadive collection.1
It ought to be observed that the date of Dr. Alcock's visit—the first week
of March—was only a fortnight later in the season than that of Mr. Hume's
visit, yet in Kiltan Dr. Alcock found a wild vine growing in great profusion which
Mr. Hume, who visited the same island, did not observe. The list contains other
instances, but this is the most striking, and it at once suggests the possibility of
this species having been introduced during the interval between 1875 and 1889,
and indicates one of the possible interests that may underlie a comparison of
this with subsequent lists.
1
This is the species referred to in Mr. Hume's paper in " Stray Feathers " as perhaps a species of
Hemarthria. Dr. King, who has very kindly examined the specimens along with me, assents to the identifi
- c a t i o n n o w m a d e . D r . T r i m e n r e c o r d s i t f r o m C e y l o n ( C a t . o f C e y l o n P l a n t s , p . 1 1 0 , [ 1 8 8 5 ] ) ; i t w a s n o t
known from Ceylon at the time that Dr. Thwaites' " Enumeration of Ceylon Plants " was published.
CA
64
Scientific Memoirs by
The subjoined table exhibits the distribution of the various species that
compose the flora (species that are purely cultivated are marked†)—
TABLE II.—Distribution of Laccadive Plants.
N A M E .
I n d i a .
C e y l o n .
N i c o b a r s .
A n d a m a n s .
B u r m a .
M a l a c c a .
M a l a y A r c h i p e l a g o .
A u s t r a l i a .
P o l l y n e s i a .
A m e r i c a .
A f r i c a .
M a u r i t i u s .
K e e l i n g I s l a n d s .
C h a g o s I s l a n d s .
Cleome viscosa
.. x
x
x
x
x
x
x
x
...
x x
x
... ...
Calophyllum inophyllum .
x
x
x
x
x
x
x
x
x
x
x
x
...
...
Sida humilis .
.
.
x x
...
x x
x
x
... ...
x
x
x
...
...
Abutilon indicum
.
. x
x
...
... x
...
x
x
...
x
x
x
... ...
Thespesia populnea .
.
x
x
x
x
x
x
x
x
x
x
x x
... ...
†Citrus acida
.
.
. x
x
...
x
x
x
x
x
x
x
x x
...
...
Suriana maritima
. .
x
...
x
... ...
x
x
x
x
x
x
x
...
x
Vitis carnosa .
.
. x
x
x
...
x
x
...
...
. . .
. . .
. . .
. . .
. . .
. . .
Cardiospermum Halicacabum x
x
x
x
x
x
x
x
x
x
x
x
...
...
†Moringa pterygosperma
. x
x
...
x
x
x
x
... ... ... ...
x
...
...
Crotalaria verrucosa . .
x
x
... ...
x
x
x
x
...
x
x
x
... ...
Clitoria Ternatea
.
.
x
x
x
x
x
x x
...
x
x
x
x
... ...
Mucuna capitata
. .
x
... ... ... ... ...
x
... ... ... ... ... ... ...
Cæsalpinia Bonducella
.
x
x
x
x
x
x
x
x
x
x
x
x x
...
†Tamarindus indica .
. x
x
x
x
x
x
x
x
x
x
x
x
... ...
†Punic granatum
. .
x
... ... ...
x x x
x
x
x
x
x
... ...
†Carica Papaya
.
.
x
x
x
x
x
x
x
x
x
x x x
... ...
Oldenlandia diffusa .
.
x
x
x
x
x
x
x
... ...
...
... ... ... ...
Ixora Bandhuca
. .
x
x
... ...
x
... ... ... ... ... ... ... ... ...
Morinda bracteata
.
.
x
x
x
x
x
x x
... ... ... ... ... ... ...
Guettarda speciosa .
.
x
x
x
x
x
x
x
x x
...
x
x
x
x
Vernonia cinerea
.
.
x
x
x
x
x
x
x x
... ...
x x
...
x
Ageratum conyzoides
.
x
x
x
x
x
x
x
x
x
x
x x
...
...
Wedelia calendulacea
.
x
x
x
x
x
x
x
... ... ...
...
... ... ...
Wedelia biflora
. .
x
x
x
x
x
x
x
x
x
...
x
... ... ...
Crepis acaulis .
. .
x
... ... ...
x
... ... ... ... ... ... ... ... ...
Launea pinnatifida .
. x
x
... ...
... ... ... ... ...
x x
... ...
Scævola Koenigii . .
x
x
x
x
x
x
x
x x
... ...
x
... ...
Plumbago zeylanica
. .
x
x
...
...
x
x
x
x
x
...
x x
... ...
Calotropis gigantea .
. x
x
...
... x
x
x
...
... ...
...
... ... ...
Cynanchum alatum
. .
x
... ... ... ... ... ... ... ... ... ... ... ... ...
Tylophora asthmatica
.
x x
... ...
x x x
... ... ... ...
x
... ...
Tournefortia argentea
.
x
x
x x
x
x
x
x
x
...
x
x
x
...
Ipomœa grandiflora
.
. x
x ...
... ... ...
x
x
x
...
x
x
... ...
†Ipomœa Batatas
. .
x
x
x
x
x
x
x
x
x
x
x x
... ...
Ipomœa biloba
.
.
x
x
x
x
x
x
x
x
x
x
x
x
...
...
Physalis minima
. .
x
x
x
x
x
x
x x
...
x
x
... ... ...
†Physalis peruviana . .
x
x
x
x
x
x
x
x
x
x
x
x
... ...
Datura fastuosa
. .
x
x
x
x
x
x x
... ...
x
x
x
... ...
Herpestis Monniera
.
.
x
x
x
x
x
x
x
x
x
x
x
x
... ...
Barleria Prionitis
.
. x
x ...
... x
x
x ...
... ... x
x
...
...
Barleria cristata
.
.
x x
... ...
x x x
... ...... ...
x
... ...
Rungia pectinata
. .
x
x
...
x
x
x
x
...
...
...
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Peristrope bicalyculata
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x
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x
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x
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x
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