96 Natural Habitats and Nativeness. 
miles away from its own place, on the soils of Chalky Boulder 
Clay and Sandy Glacial Gravel. Introduced without doubt, 
because it is transient; but by what means? A little reflection 
and the problem was solved. ‘IT. E., whocarts the road stone has 
no land where T. arvense grows; but stay, he begged a few loads 
of mangels from his neighbour G. S., last winter, while he was 
busy carting the road metal. This plant grows freely on the 
’ 
latter’s land where “ the pie” is situated. ‘There can be no doubt 
when the stone was shot out of the dry cart, the seeds left by the 
damp mangels came along with them. Here they are imper- 
manent, because this species is not a Frequenter (3) of pasture, or 
(4) of meadow. When the roadside pasture returns with irresist- 
able power, as it will in a few years, these places will know 
T. avvense no more. If the land, where it has flourished so 
well at Cadney for forty years, were sown down to grass (3), or 
planted as wood-land (5), it would quickly disappear there too ; 
as it would also on the Lincolnshire Limestone (2), from which 
it was originally imported, though it is no true native there. 
With us T. avvense is not only a Follower (2) of cultivation, 
itis an uncertain one too. Though it is found round most local 
flour mills, it is generally absent from the most suitable soils ; 
and even where there are allotments, it is often confined to one or 
two patches in a dozen or more. 
Another such case is that of Hypocheris glabra. During the 
last thirty years it has been diligently sought for by Messrs. F. 
A. Lees, W. Fowler, H. Fisher, and Miss S. C. Stow, on soils 
which appear ideal for it, if it were with us permanently. Mr. H. 
C. W. Hawley found it between Coningsby and Tumby, on Old 
River Gravel, on arable landin 1goz. It has remained there till 
to-day, but only as a rare Follower (2) of cultivation, nothing — 
more, even on such a suitable soil. 
Such cases are simple and amenable to analysis. Are the so 
called complicated cases much more difficult ? Take Urtica dioica 
as a fair example. It has so attached itself to man, that if you 2 
are on a coach ride on the wildest Scotch or Irish moors, and an 
isolated bed comes into view, the driver may point it out with his 
