CHAP. VI. 
HYBRID PLANTS. 
289 
Europe; and altogether about forty cases of wild reputed 
species have been collected by Schiede, Lasch, and De Can- 
dolle. It is difficult not to believe that a great number of 
the reputed species of Salix, Rosa, Rubus, and other intricate 
genera, have also had a hybrid origin. 
This, as De Candolle justly observes, is an answer to those 
who, like Linnaeus, have assumed that the number of species 
of organised beings has been constantly augmenting, since the 
creation, by the intermixture of different races. All the ob- 
servations that have been made for the last century have not 
produced a catalogue of 50 certain hybrids in a wild state. 
In a practical point of view, I am inclined to believe that 
the power of obtaining mule varieties by art is one of the most 
important means that man possesses of modifying the works of 
nature, and of rendering them better adapted to his purposes. 
In our gardens some of the most beautiful flowers have such 
an origin ; as, for instance, the roses obtained between 
R. indica and moschata, the different mule Potentillae and 
Cacti, the splendid Azaleas raised between A. pontica and 
A. nudiflora coccinea, and the magnificent American-Indian 
Rhododendrons. By crossing varieties of the same species, the 
races of fruits and of culinary vegetables have been brought 
to a state as nearly approaching perfection as we can sup- 
pose possible. And if similar improvements have not taken 
place in a more important department, — namely, the trees that 
afford us timber, — experience fully warrants the belief that, 
if proper means were adopted, improved varieties of as much 
consequence might be introduced into our forests, as have 
already been created for our gardens. 
It is, however, to be regretted that those who occupy them- 
selves with experiments of this kind do not confine them to 
woody or perennial plants which can be perpetuated by cut^- 
tings. Mule annuals have the great fault of perishing almost 
as soon as they are obtained, and they serve no other purpose 
than that of encumbering the records of science with accounts 
of plants which, from their transitory existence, can never be 
re-examined. 
In conducting experiments of this kind, it is well to know 
that, in general, the characters of the male parent predomi- 
u 
