DEPENDENT PLANTS 41 
Observation and study.—With some good specimens of 
dodder growing upon its host plant study carefully the rela- 
tions existing between the two. Is the dodder attached to 
the soil? How is it attached to its host plant? Make a sec- 
tion through one of the attaching roots and see how it is 
arranged for holding and for absorbing nourishment. Draw. 
Note the relative vigor of the two plants, and determine 
the effect of this relationship upon each one. A study of 
a region in which many dodder plants are growing will be 
instructive. 
Some seeds of the dodder should be collected and planted 
in a box in which other plants are growing. This will enable 
you to see just how dodder plantlets get started upon their 
host plants. 
If specimens of mistletoe upon pieces of its host can be 
had, note the following points: 
Is mistletoe devoid of chlorophyll? What does this indi- 
cate? Cut into the host plant at the base of a mistletoe 
plant and see where the absorbing region is, and how it is 
arranged. Account for its position and form. How are the 
seeds of mistletoe distributed? Study the other parasites at 
hand, noting how they are arranged with reference to their 
hosts, and how they take their food material from the host. 
Make sketches and notes descriptive of each. 
Do all the parasites grow thriftily? Do they ever cause 
the death of the host plant? Are there any cases in which 
they do not seem to injure the host plant? Observe in your 
walks whether the distribution of these plant parasites is 
general, and the various effects they produce upon their 
hosts. 
LESSON XXII 
Saprophytes 
Materials Molds of various kinds growing upon fruit, 
exposed leather, etc., toadstools, mushrooms, and puffballs. 
