938 Marvels of the Universe 
Many of our common British weeds, 
though less formidable in their armament 
than these African terrors, are equally per- 
sistent in their demand for a free passage 
and equally ingenious in the means by 
which they effect it. It has been re- 
marked already that most of the vast 
Composite family—thistles, groundsel, 
dandelion, etc.—rely upon the wind to 
waft their plumed seeds hither and 
thither. But in the common burdock the 
plumes are too short and stiff to act as 
sails for the heavy seeds, so the plant 
arms each of the numerous scales sur- 
rounding the flower head with a strong 
THE BULLOCK-HEADED NUT. hooked point which readily catches upon 
Bem paaraiana te iam ana crmer )) Cuolctell alas o: Che cotines of men, 
Hedhon inno ccas costed bp dhs ain hom, Is acl mark] lnc! SO Uno winolle seaclneadl is camnledl away 
probably Bouse ifpit wereite fall on the EIROLINEL as it needs the hard and gradually drops its seeds to colonize 
case to be soaked in the water before germination can commence. 
fresh ground. 
Another member of this family which has obtained a footing (not, let us hope, a permanent one) 
in this country as a weed of cultivation is the burweed, a coarse annual about two feet nic 
has discarded aviation altogether as a means of seed dispersal, providing no wind-hairs, but relying 
instead upon the hooked prickles with which the female flowers arm their burs. The burs are small, 
but get into sheep’s wool in such numbers as to prove a sore trial to merchants, and this has been 
the means of disseminating the plant into the whole of the temperate world. Originally indigenous 
to the Mediterranean region, the loss it has caused to Australian sheep-farmers has been reckoned 
in some cases as high as fifty per cent. The traveller Frauenfeldt saw horses in Chile in 1860 with 
their manes and tails so heavily tangled with these burs that they could hardly walk. In 1871 
it was first noticed in this country growing 
near Edinburgh. 
The common carrot, forget-me-not, 
goose-grass or Robin-run-the-hedge, and 
enchanter’s nightshade are among other 
herbs which have recourse to hooks to 
secure the means of colonization; and 
although familiarity may blunt our ad- 
miration for the ingenuity of the 
mechanism, it is not any easier to account 
for its development than it is for that of 
less common or more elaborate armature. 
We come now to plants that shoot their 
ripe seeds away to a considerable distance. 
The scentless dog-violet is a good example 
aac e Ba) ; Bee OG of this. The capsule containing the 
THE DEVIL'S HORNS. S 
eel cree fp CE canis Gammty Tie ceded ino ts de  SUMOOUN Seees Inamgs down at first, but 
grass with its formidable horns curved upwards. These hook them- when ripe stands erect above the leaves, 
selves into the nostrils of grazing animals. and irritation is set up 
which causes the poor creatures to rush about wildly shaking their and opens Im three equal valves, exposimg 
heads, and so dispersing the contents of the half-opened pod. the seeds. Then the valves begin to 
