518 WHITE: THE SALTATORY 
Mutation is, therefore, the saltatory origination of new organic 
species resulting from sudden molecular change in their initial 
protoplasts. The new species is at once such, without preliminary 
preparation, without intermediary gradation, and without any sub- 
sequent addition of attributes. Newly mutated species differ 
clearly and distinctly, but not widely, from the parent species. 
Wide differences between species of a genus indicate the death of 
intervening species. As a rule, mutation occurs, not by, or in 
connection with cross-fertilization, but in correlation with pure 
intraspecific sexual reproduction, and nevertheless independently 
of it. A new and stable specific form is thus produced, but the 
parent species remains intact. Mutation is, therefore, a strictly 
phylogenetic process, although plural cases occurring in one and 
the same mutating species are often randomly divergent in character. 
Hybridization occurs in nature, and very often in cultivation, 
but it is not mutation. Neither is it really phylogenetic in char- 
acter, but a result of ontogenal miscegenesis, with the groups of 
molecular specific units unbroken in each parent germinal portion. 
According to Mendel’s law, even fertile hybrids are sooner or later 
obliterated by the prepotency of one or the other of the parent 
forms. 
Mutation, being a normal process, does not produce monstrosi- 
ties, The latter are cases of distorted or abnormal ontogeny. 
Above all, variation is not mutation, nor are varieties incipient 
species. Ordinary fluctuating, or individual, variation is an insepar- 
able accompaniment of all plants, and racial variation also widely . 
prevails, but no kind of variation leads to mutation proper. ; 
Mutation, being a result of intracellular molecular change, !§ 
necessarily sudden, as is molecular substitution in chemical aces 
tion. One cannot concieve that molecular change could continue 
in action toward one result through immeasurable time. A species 
being suddenly produced implies that its normal state is one of at 
~ least a considerable degree of stability. 
Species being normally stable and only incidentally 
part of the time-existence of each is therefore a mutative, 
part an immutative, period. The immutative period is, a5 @ rule, 
so very much longer than the mutative period that very few mut 
able plants exist simultaneously in any flora. Because of thes? 
mutable, a 
and a 
