320 Field, Forest, and Wayside Flowers 
to produce offspring inheriting the habits of their 
parents, and of these offspring the more tender 
and defenceless will be eaten, while the thorniest, 
stringiest, or bitterest individuals will be spared, 
to produce offspring thorny, stringy, and bitter, 
like themselves. So, in the course of generations, 
Nature brings into being a number of plant-fam- 
ilies, each protected from browsing animals by 
some well-marked peculiarity.’’ 
The common mullein, a plant of the roadsides 
and pastures, is rendered unappetizing by the down 
which covers its leaves, and which, it seems, is 
doubly useful. For ‘‘ hairs,’’ says Vines, ‘‘ often 
serve to diminish transpiration and radiation, and 
to screen chlorophyll from too intense light, and 
a clothing of hairs is characteristic of plants which 
habitually grow in dry soils and in sunny situa- 
tions.’’ But in this case the fuzz which clothes 
the mullein-leaves makes them as ‘‘ dry eating’’ as 
so much flannel. 
The great cool leaves of the burdock are bitter 
and sour exceedingly (Fig. 90). So efficient are 
these devices of Nature for the protection of this- 
tles, mullein, and burdock, that they are generally 
spared, even in close-cropped pastures. The dan- 
delion and wild lettuce-leaves contain a bitter juice. 
