6 
two distinct means must be kept in view as necessary. When 
annual weeds are to be dealt with, the difficulty is not so great as 
in those cases where perennial plants have to be subdued. What- 
ever method is adopted for getting rid of plants seeding only once 
from the same root when left undisturbed, it reduces itself to acting 
on the principle of destroying the plants before they can ripen any 
seeds. In the case of Thistles and allied plants of annual growth, 
when the individual plants are cut or lifted, they should im- 
mediately be brought into heaps and be burned at once, otherwise 
the seeds may ripen still on the plants ; inasmuch as though dis- 
lodged or cut, they are apt to retain vitality for some considerable 
time while on the ground, all Thistles being succulent and slow' in 
drying up. The difficulty of dealing successfully with Thistles 
and other weeds of perennial growth is much greater ; and regret- 
ably the worst of all European Thistles, Carduus arvensis, has in 
late years made its appearance also here. The difficulty of its 
eradication is augmented, because the root is ramified and fragile ; 
besides, the smallest portion left near the surface will continue 
to grow. Here it may incidentally be mentioned, what Dominique 
Villars already asserted, in the last century, that Carduus arvensis 
could best be subdued by not interfering w r ith it till after flower- 
ing. So it would seem, that the root gets much exhausted by the 
far advancing growth of the plant, without the danger of seeds 
ripening being readily incurred by this almost unisexual Thistle. 
Villars pointedly says, that by any early cutting the plant would 
increase in all directions from the root. As this Carduus is in 
our colony of comparatively recent introduction, this advice could 
not yet be much brought to test here; it is not applicable how- 
ever to Thistles of only annual duration, and would probably be 
neither of avail, when Carduus arvensis has become a plant of 
several years' age. 
It would seem, that for providing an expeditious, effective, and 
uncomplicated “ Weeds-Destroyer,” the ingenuity of invention 
can still further be exercised, with a view of superseding to some 
extent manual application by usual hoes, forks, scythes, spades, 
ploughs or other tools. ^ Beyond the ordinary operations and 
implements in rural use for the destruction of weeds of various 
kinds, some contrivances exist perhaps not yet adopted here. 
Thus attention is directed, where locality admits of application, to 
a particular “ Paring Plough,” which cuts the roots readily under 
the surface, and thus prevents the plant forming several side-stems, 
as it is prone to do when cut just above ground. In some cases 
depasturing can be resorted to, particularly by sheep, and perhaps 
goats and pigs, as the continued deprivation of stem and leaves be- 
eomesat last detrimental to the root; thus sheepwill nipoff the young 
sprouts of Carduus arvensis with avidity ; and if this is carried 
on sufficiently long, the roots will perish of exhaustion. The 
* Here tlie “ Thistle-hoe u (a small lifting spade) and the “ Thistle-chopper ” are chiefly 
utilized. 
