4 HEREDITY, AND THE ORIGIN OF SPECIES. 
viously made. We need not, at this time go into the 
intricacies of the arguments that cluster about this main 
thesis, or weigh the evidence that is drawn from the pres- 
ence of useless, vestigial, and useful characters in various 
organisms. 
Popular belief in the influence of environment and the 
inheritance of acquired characters finds its commonest ex- 
pression in “that plants have been changed by cultivation.” 
Domesticated races are spoken of as “garden forms” by 
botanists and horticulturists, with the implication that they 
are specialized types resulting from the effects of tillage. 
Now so far as actual cultivation is concerned, this assump- 
tion is without foundation, since at the present time no 
evidence exists to show that the farm, garden or nursery 
has ever produced alterations which were strictly and con- 
tinuously inheritable, or were present, except under envi- 
ronic conditions similar to those by which the alterations 
were produced, although vague statements and erroneous 
generalizations to the contrary are current. It is true of 
course that structural and physiological changes may be 
induced in a strain of plants in any generation, which may 
persist in a share to the second, or even in some degree to 
a third, but no longer. Some very important operations of 
the market gardener and the farmer are dependent upon 
this fact. 
The possibility that permanent changes might be in- 
duced is by no means to be denied, and it is a fair subject 
for investigation. Actual evidence is to be obtained only 
by observations of breadth under guarded conditions. Until 
this is at hand all affirmative conclusions can be but it- 
ferential and suggestive. 
Vicinism, the somatic multiplication of bud - sports 
and extreme variants from a fluctuating series, and the 
confusion of closely related elementary species form the 
basis for the greater number of mistaken assertions as t0 
