58 The Different Modes of Origin of new Species. 
inquire how far their transference to systematic varie- 
ties is justified. 1 
The origin of horticultural varieties will therefore 
be submitted to a critical and experimental examination. 
But before we do this I think it advisable to consider 
first the meaning which is attached to the term variety 
in systematic works, and secondly the various ways in 
which species can arise. And we shall find that whilst 
there is no question that the mode of origin of horti- 
cultural varieties is often analogous to that of so-called 
"good" species, this parallel is by no means so common 
as the present form of the doctrine of descent would lead 
one to believe. 
To begin with systematic varieties : Here we find we 
can draw a pretty natural line between what we called ele- 
mentary species on the one hand, and real systematic 
varieties on the other. 
In connection with this antithesis I think it desirable, 
after what has already been said on this topic in the first 
volume, 2 to lay especial stress on the fundamental dif- 
ference between these two conceptions. LINNAEUS and 
his pupils describe the elementary species as varieties ; 
JORDAN, DE BARY, and others who argue from experi- 
mental data, refer to all forms as species. 
The terms "species" and "variety" have become so 
familiar that it is no longer possible to effect any radical 
change in their definition. For their exact meaning we 
have to refer to the works of LINNAEUS himself. His 
1 For some interesting observations relating to the origin of new 
forms, see the papers by F. KRASAN in ENGLER'S Botanischc Jalir- 
biichcr. Vol. XIII, Pts. 3-4; Vol. XXVIII, Pts. i, 2. and 5, and also 
his Mittheilungen ilbcr Cultiirvcrsuchc mit Potcntilla arcnaria, Graz, 
1900. 
2 See Vol. I, 7, "Species, Subspecies and Varieties," especially 
pp. 169-172. 
