MANUAL OF NATURE) STUDY. 
125 
found now-a-days along public highways and "waste 
places. How did it get there ? Collect some wild 
lettuce and examine the implements for travel 
through the air. After breaking prairie sod, espec¬ 
ially in the low ground, cottonwood shoots spring 
up quite plentifully, even when there are no trees 
of that kind within a radius of several miles. How 
do you account for it ? Examine the provision that 
nature has made for floating the seeds and find 
your answer in that. 
The first jimson weeds in America sprang up 
with the tobacco around Jamestown, early in the 
17th century. Where did they come from ? How ? 
To-day they are found in many rubbish piles and 
hog lots all over America. How do you account 
for such a widespread distribution ? Here, again, 
an examination of the burr should be given. What 
other seeds are distributed in like manner? The 
pupils will name cockle-burr, Spanish needle, beg¬ 
gar lice, many achenia such as buttercup, hepatica, 
anemone, etc. 
Prof. D. S. Kelly, of Jeffersonville, Indiana, fur¬ 
nishes the following interesting account of weed 
distribution in the west: 
“ Not until a few years ago was the Solatium ro- 
stratum found east of Colorado; but when travel 
began eastward along the old trails through Kansas, 
