Thistlés and Nettles 341 
ple tubes they will gormandize the sweets there, 
so that the robbed florets will have no inducement 
to offer to butterfly or bee, and it is extremely 
unlikely that an ant will pay for her refreshments 
by carrying the pollen where it ought to go, to 
another flower of the same species. 
So there has been a warfare, summer after sum- 
mer, for no one knows how many years, between 
the ants, which want to get into the purple tubes, 
and the thistle-plants which want to keep them 
out. 
The devices of the thistle to this end are many _ 
and wonderful. Beginning at the ground (as the 
‘ant does), we find that the stem of the plant is 
clothed all the way up with fuzz or hairs. This 
makes things unpleasant for the crawler, for ‘‘ noth- 
ing,’’ says Sir- John Lubbock, ‘‘ bothers ants like 
hairs.’’ In some varieties of thistle the stem looks 
as if it had been wound around and around with 
spider-webs, and often these are gummy, and likely 
to catch the crawling insect as it tries to work its 
way up. 
Along the stem, here and there, are leaves. 
These in many varieties have horny edges which 
roll backward, making a barrier which the ant 
finds it very difficult to surmount. The under 
