Agricultural Weeds. 
377 
matter, farmers should be particular not to allow a dirty patch to 
stand for seed, although it may he " tlie most profitable thing they 
could do with it." 
Weeds in Mamire. — It is too much the custom to consider 
that the power of germination of seed is destroyed by decompo- 
sition in manure heaps. That some are so when the manure has 
been thoroughly decomposed there can be no doubt ; but many 
are not, and with those that are the process is too uncertain to 
be relied upon. We have seen quantities of pulled docks and 
of crow-garlick thrown upon a heap to decay, and afterwards 
noticed vetches manured therewith to be full of these trouble- 
some weeds. Neglected manure-heaps are often covered with a 
profuse vegetation, which thereon produce enough loeed-seeds to 
stock a farm. In these cases the plants rendering the original 
seed were doubtless mixed with the straw of which the manure 
was made ; and yet, notwitlistanding the vicissitudes they had 
to contend with, were not destroyed. Too much care, tl;ere- 
fore, cannot be taken to prevent this source of mischief, to which 
end it will always be found best to burn pulled weeds ; and in 
harvesting corn, docks, thistles, and the like should not be bound 
up with the sheaves, but, if practicable, left standing, and after- 
wards destroyed. 
Seeding of Weeds. — One of the most fertile sources of the 
continuation of weeds is that of constantly allowing them to seed 
on the land. Now, the enormous increase which may result 
from seeding may be gathered from the following table of observ- 
ations made upon a few of our common species : — 
Table III. — Estimation of the probable Power of Increase of Weeds. 
Number 
Number 
Number 
of Seeds 
of Seeds 
Botanical Name. 
Common Name. 
of 
each 
on a 
Flowers. 
Flower 
single 
may bear. 
riant. 
Senecio vulgaris 
Groundsel 
130 
X 
50 
6 . 500 
Stellaria media 
Chickweed 
50 
X 
10 
500 
Agrostemma githago 
Corn Cockle 
7 
X 
370 
2,590 
Lychnis dioica 
25 
X 
3 37 
25,137 
Papaver rhceus 
100 
X 
500 
50,000 
Sinapis arvensis 
400 
X 
10 
•i,0(<0 
Galium tricorne 
Black mustard .. 
200 
X 
6 
1,200 
Corn bedstraw . . 
100 
X 
2 
200 
,, aparine 
550 
X 
2 
1,100 
Sonchus arvensis 
Corn sow thistle 
100 
X 
190 
19,000 
Carduus nutans 
Musk thistle 
25 
X 
150 
3,750 
iEtliusa cynapium . . 
Fool's parsley . . 
300 
X 
2 
GOO 
Ervum tetraspermum 
Tare 
60 
X 
3 
180 
Daucus carota 
Wild carrot 
600 
X 
2 
1,200 
Pastinaca sativa 
Wild parsnip 
600 
X 
2 
1 ,200 
