PLANTS MULTIPLY BY MEANS OF STEMS. 15 
is a little plant packed ready for transportation. This sec- 
ond mode of spreading will be described on a future page. 
Fig. 8. — Plant of a black raspberry showing one branch (stolon) with several tips rooting. 
10. Living branches snap off and are carried by water or 
wind. — Some trees and shrubs among the willows are 
called snap-willows, because their branches are very brit- 
tle ; on the least strain from wind, rain, sleet, or snow, the 
smaller branches snap off near the larger branches or the 
main trunk, and fall to the ground. At first thought 
this brittleness of the wood might seem to be a serious 
defect in the structure of the tree or shrub, although 
they seem to produce branches enough for their own use. 
But the branches, which are strewn all around after 
a storm often take root in the low ground where they 
fall ; some of them are carried down stream by the 
current, and, lodging on the shore below, produce new 
trees or bushes. During the winter of 1895 and 1896 a 
