THE COW-TREE. 63 
to their children ; and you might fancy you saw 
the family of a cowherd gathering around him, 
and receiving from him the produce of his kine. 
We drank a considerable quantity of it in the 
evening before going to bed, and very early in 
the morning, without experiencing the slightest 
injurious effect.” The name of this remarkable 
tree is the Palo de Vaca, or Cow Tree, it is a 
relative of the humble nettle which grows by our 
way-sides. A similar tree, called Hya Hya, 
flourishes in the dense forests of British Guiana, 
and produces a milk of an agreeable flavour in 
such abundance, that some travellers, having once 
felled one of a large size that stood near a brook, 
found that, in the course of an hour, it coloured 
the water quite white and milky. It is time, 
however, that we now retrace our steps, and 
proceed to the leaves of the plant. 
Taking the course of the ascending sap as our 
guide, we are conducted into one of the most beau- 
tiful and important studies of the whole vegetable 
history. The clear stream of fluid penetrates 
swiftly along the minute woody tubes, which 
form the outer portions of the stem, carrying dis- 
solved in it many soluble chemical salts, obtained 
