1878. ] How T; histles Spin. 645 
‘The leaves of several other plants, like the Concord grape, 
Centaurias, etc., are covered in a manner similar to the leaf of the 
thistle. The branching hairs of the mullein and leaves of button- 
wood, when very young, are like those of the thistle, only the 
extremities are not sticky. 
In the New Testament 
we read, “Consider the 
lilies of the field, how they 
grow: they toil not, neither 
do they spin.” This was 
not said of thistles nor of 
-grape vines. 
The thread of the this- 
tle is single and slowly 
drawn out. Perhaps it 
may be called a clumsy 
affair when compared to 
the delicate cable of the 
spider, with its numerous 
strands. The thread of 
the thistle answers. well 
enough the purposes for ý . 
which it is intended. It Margin of scale of involucre, full grown. 
protects the plant from sudden changes of weather, 
keeps the rain from wetting the surface, and probably 
to some extent keeps enemies from injuring the plant. 
There is one other fact of interest about the thistle 
under consideration. When full-grown the scales about 
the heads of flowers have each an oblong gland just at 
gland. The object of the gland I am as yet unable to Pagers?) 
determine. It may and probably does attract insects. mum show- 
It often entraps them. I have many times seen six to ing E kana 
ten small flies and Hymenoptera, some of them half an 
inch in length, held fast by mouth or legs or wings. Here they 
buzz and twist and pull till strength and life are exhausted. 
Whether this is of any use to the plant for food or amusement, 
to keep away larger insects, or to attract spiders or ants, I have 
not yet ascertained. 
