124 JOURNAL OF THE PLYMOUTH INSTITUTION. 
nothing more than climate and soil combined that has prevented 
its further advance in this direction. It seeds very abundantly, and 
does not seem to have to depend on insects for effecting the work 
of fertilization. It looks like a species which in the struggle for 
life has not been as yet able to get further forward in a south- 
westward advance. 
In Acer campestre, L., we have an example of the apparent want 
of power in an arboreal species to spread in a similar direction. 
The maple is quite a common bush in South-east Devon about 
Chudleigh and some of the adjoining parishes, occurs about Totnes 
and Newton, extends to Ugborough, Newton Ferrers, and Yealmp- 
ton ; but in the latter neighbourhood becomes somewhat scarce 
and local, until about Plymouth we only see it in a few spots, and 
these are, with the exception of a station or two at or near Mount 
Edgcumbe, all on the eastern side of the Tamar. Thence, through- 
out all the southern portion of Cornwall, the maple seems to be 
unknown in an indigenous state. It looks as if some opposing 
influence to its south-western extension became gradually more 
and more powerful until it ultimately absolutely barred onward 
extension. The restricted distribution in Britain of this certainly 
indigenous species affords a noticeable contrast to the occurrence 
from north to south of its near ally, the common Sycamore, Acer 
pseudo-Platanus, L., notwithstanding historical evidence goes far to 
favour the view that this latter is an alien species, introduced at a 
comparatively quite recent time. Gerard, who was gardener to the 
great Lord Burleigh, speaks of it in the days of Elizabeth, as " a 
stranger in England," adding, " only it groweth in the walkes and 
places of pleasure of noble men, where it expecially is planted for 
the shadow sake, and under the name of Sycomore." The readi- 
ness with which it springs from self-sown seed, and under ordinarily 
favourable conditions rises into full development, shows how 
quickly an introduction may settle itself among the indigenous 
flora of a country and maintain a successful struggle even in one 
fully stocked with aboriginal species or earlier immigrants. It has 
occurred to me that in the case of the common maple the abundant 
moisture of the extreme south-west may be unfavourable to the 
full development of the seed, though fruit may be seen in some 
seasons on bushes in the neighbourhood of Plymouth. 
Of the large order Legwniniferw several species of Trefoil and 
others show a marked partiality for the coast or the neighbourhood 
