The Making of Species 
Our contention, then, is that new species, in 
the ordinarily-accepted use of the term, do not 
arise as a rule by one sudden bound (although 
they may sometimes do so), but are the result of 
the accumulation of several mutations or dis- 
continuous variations. Some of these mutations 
are exceedingly well marked, while others are so 
small as to be indistinguishable from the more 
extreme fluctuating variations. Before passing 
on to consider some cases of well-marked muta- 
tions which have occurred among animals and 
plants, we should like to take this opportunity of 
pointing out that as regards experiments in 
evolution the botanist is far more favourably 
situated than the zoologist. 
The botanist is able to reproduce many species 
vegetatively, e.g. by cuttings, and is thus easily 
able to multiply examples of mutation. He can 
also reproduce the great majority of plants by 
self-fertilisation, and so experiences no difficulty 
in “fixing” a new form. Again, plants are far 
easier to control than animals; as a rule they can 
be transplanted without any impairment of their 
capacity for breeding. Moreover, they produce 
a greater number of offspring than the most 
prolific of the higher animals. The animal 
breeder is thus at an obvious disadvantage as 
compared with the horticulturist. It is only 
with great difficulty that he can fix the mutations 
which appear in his stock. 
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