10o0 THE STORY OF PLANT LIFE 
The effect of this poison is narcotic, and owing to its 
rapid action on the nervous system, a conyulsive 
contraction of the muscles of the jaw generally 
prevents the use of emetics.”’ 
THE BLACKTHORN (Prunus spinosa). 
The snowy white blooms of the blackthorn in early 
Spring dotted over the country make the same effect 
that the Whitethorn or May does in May. And when 
all the hedges are leafless the contrast with the black 
stems and branches is all the more striking. 
Blackthorn is found in every county and grows at 
a height of 1300 ft. in Yorkshire. 
The Sloe or Blackthorn forms scrub or til on 
the outskirts of woods, indicating a return of meadow- 
land to a more natural state, or from primitive wood- 
land to scrub. 
This scrub occurs in the midst of true woodland, 
and on the outskirts may also be natural. It is 
frequent in hedgerows and on the sides of roads, 
where it is usually planted. This gregarious or 
social habit gives it a distinctive character and is 
general, save where it is found isolated amongst 
Hawthorn, Cornel or Buckthorn in the hedgerow. 
Sloe has the bush habit. It may be recognised, as 
the second Latin name implies, by the marked spinous 
character of the branches, and bythe zigzag arrange- 
ment of the ultimate branches. The Bullace lacks 
these two characters, and the branches are more erect, 
