sheep, or to the fur of other quadrupeds, and ulay thus be
carried from one place to another. That., there is truth in
this conjecture, we may learn from the observation made by
De Candolle at Montpelier. This, however, as Rudolphi observes,
cannot here be a method of dispersion attended with
- very important results.; Seeds could scarcely be conveyed by
quadrupeds to very distant places.
Seeds are frequently carried by birds after being swallowed,
and they have been ejected without having their,vitality impaired.
Some seeds are even in a state more fit for vegetation
after passing through the stomachs of birds, a fact of which
Mr. Lyell has mentioned a singular' proof. Far mer s, in som e
parts of England, who wish to plant quick-set hedges,-[cause
the seeds of the white-thöm to be first eaten by turkeyS> ;in
order to hasten "the growth of the plants which spring_from
them.* The seeds of the Misletoe and Juniper are well
known to be conveyed by birds.
Wildenow advanced the opinion, that the great number of
water-fowls which migrate annually from cold and warm
climates, are the principal means of rendering marine plants
so widely dispersed as they are known to be ; by carrying.with
them the seeds of such plants,.either in their stomachs,irpr
adhering to their feathers. Rudolphi, however, declares,'that
he has examined, a great variety of water-fowls and other
birds of passage, without ever finding seeds adherent to
them. He adds, th a t the birds of passage arrive in an extremely
lean state, and with their stomachs perfectly; empty,
thus precluding all probability of their conveying undigested
seeds.'f*
These considerations render'it improbable, that birds perform
a very important part in the diffusion, of seeds to distant
places ; but they occasionally convey even large seeds
from one tract of country, and probably from one island to
another. Mr. Lyell has cited the relation of Captain Cook,
who says, that Mr. Forster shot a pigeon with a wild nutmeg
in its crop: this happened in the Isle of Tanna, where no
* Lyéll’s Principles of Geology, book 3.
•j* Wildenow, Griindriss dér Krauterkunde, 3 auflag. Rudolphi, über die Ver-
breitung der Pflanzen, p. 116.
nutmegs ever had been found.# Ï was lately informed, that a
piebe of ground, in Herefordshire; which had been a grove
o f’fir-trees, and which had been laid bare by fire, was afterwards
Covered by oak-trees,v which sprang up spontaneously.
A person who was surveying thê ground;and wondering
at the appearance- of the young wood of oak-trees, happened
upon the spot to shoot a1 j-hy with an acorn in its mouth,
'and’ hb'cbncluded', th a t he Had thus found a clue to what
had appeared a mystery. ‘
• By far j the most im p o r ta n ^ l^ ^ É K iR the diffusion of
seeds, are, doubtless, those of the atmospherd and of water.
P aragraph 3.—Diffusion of seeds by means of the atmosphere.
.
Ruidolphi contends, that the diffusion of plants by means
pf aerial currents/must be of mo.redlmited influence than it is
commonly l®)poseu4ö be. He thinks, that winds can scarcely
convey,even • . t h o s e w h i c h are provided with pappi or
“vy’inglets-over many miles, or further than the" Immediate
vicinity of places where they originate : plants could only thus
be widely spread when their dispersion is continuous, and
;nl ^ aterru p tëd by great intervals; of' space : when the same
spltde^are fötind in the mountains of Lapland, and in the
AfpV o,f Switzerland, without appearing-in the intermediate
countries, it is difficult to 'suppose1, as Rudolphi has remarked,
that they could have been' Spread from bne-'of thefe places
Id the other by means of aerial currents. This writer deems
it impossible to explain by this or any other known method
Of diffusion, Sjuch facts as* those observed’ by Olof Swartz,
who found European mosses in the mountains of Jamaica,
and even several of the phanerogamous, plants of Europe,
as scirpus lacüstris and autumnalis,. hydmcotyle vulgaris,
alsine media, euphprbia chameèsycè,/ sisymbrium nasturtium,
medicago lupulina, indigenous in the West India
islands. He remarks, that M. de Humboldt found, in the
mines of New Spain, the same subterranean cryptogamoüs
plants which are known to grow in deep excavations of the
* LyeR’s Geology, Book 3,ch. 5.