Bugloss and Scorpion Grass 241 
the parent plant, and if you will walk where the ter- 
restrial species grow you may speedily find out how 
they are carried: the bottoms of your trousers, or 
hem of your skirt in the case of a lady, will be found 
thickly studded with the calyces of these plants. 
They similarly catch in the coats of mice, shrews, 
rabbits, weasels, birds, and around the legs of sheep, 
dogs, and foxes, which shake out the nutlets as they 
walk or run. 
The two species, M. palustris and IM. cespitosa, 
which grow half-submerged in streams and ponds, 
present such a contrast as proves conclusively what is 
the reason for hairy stems and leaves and hooked 
calyces. There are a few hairs on the stems, but the 
leaves are so smooth that they shine, and the calyx is 
furnished only with straight simple hairs which lie 
close against it. The reason for the difference is 
obvious: ants cannot steal the honey or pollen if the 
plant is surrounded by water, though this may be the 
thinnest layer possible, and hooks on the calyx are 
unnecessary where the water is the best carrier of 
the seeds which are not wanted to be scattered on 
land. 
