Vegetative Mutations. 615 
the evidence bearing on them. Most of the later writers 
have agreed with him. DELAGE opposes the view that 
fertilization is the sole cause of variability, partly on 
the ground of the existence of bud- variations, partly 
because nothing new is produced in fertilization, in which 
nothing more occurs than a recombination of heritable 
characters already present. 1 SAVASTANO gives many rea- 
sons, derived chiefly from the study of woody plants, in 
support of the view that varieties usually arise from seeds 
and more rarely from buds. 2 BAILEY, on the other hand, 
lays greater stress on bud-variations. According to him 
bi-sexual reproduction is not a condition of variability, 
since many new varieties have arisen by vegetative means, 
such as several sorts of pine-apples, bananas, strawberries, 
apples, weeping willows, etc. 3 
KASSOWITZ goes furthest in this direction when he 
says: 4 "Even if there had never been any sexual repro- 
duction, our earth would be peopled by beings differing 
widely from one another in their characters and in their 
functions ; and there is no ground for the assumption that 
the differences between the most widely separated forms 
would have been any less without this (i. e., sexual re- 
production) than it actually is." 
The conclusion from this all too brief historical sur- 
vey is that the importance of vegetative mutations is 
gradually obtaining wider recognition, whilst the attempt 
to associate species-forming variability with fertilization 
is coming to be regarded with less and less favor. 
1 Y. DELAGE, L'heredite, 1895, P- 283. 
2 L. SAVASTANO, La Varicta in arboricultura, Annali d. R. Scuola 
Sup. d'Agricoltura in Portici, 1899, I 2 - P- 63 and elsewhere. 
' L. H. BAILEY, The Plant Individual in the Light of Evolution, 
Science, 1897. 
4 MAX. KASSOWITZ, AUgemcinc Biologic, II, 1899, p. 247. 
