PERSONALITY OF PLANTS 
That some plants are parasites from neces- 
sity or laziness rather than choice is indicated 
by a Brazilian variety of the Cuckoo-Pint 
which sits far up on some tree branch and, like 
an immense spider, sends down to the earth 
long delicate tubes through which it some- 
times sucks food and water. 
One of the most interesting facts in plantdom 
is the alliance maintained by Clovers, Beans, 
Vetches and other leguminous plants, with 
Bacteria belonging to the class Pseudomonas, 
No soil can be fertile unless it contains organic 
compounds of nitrogen. The earth Bacteria 
have discovered methods of producing these 
important substances, possibly extracting nit- 
rogen distributed through the ground. ‘These 
minute parasites attach themselves to the roots 
of the larger plants, which promptly enclose 
them in cysts or nodules where they can lead 
a sheltered life and manufacture assimilable 
food compounds for their hosts. When they 
die, the owners of the roots feed upon their 
bodies. 
What is the art of grafting but a form of 
artificial parasitismr Very often a branch or 
[06] 
