the effect is due to the wound or to the injection of
fluid as such, or to its chemical properties. This, however, is not so
essential as to decide whether the mutant stands in any relation to the
influence of external factors. It is at any rate very important that
this kind of investigation should be carried further.

If it could be shown that new and inherited races were obtained by
MacDougal's method, it would be safe to conclude that the same end might
be gained by altering the conditions of the food-stuff conducted to the
sexual cells. New races or elementary species, however, arise without
wounding or injection. This at once raises the much discussed question,
how far garden-cultivation has led to the creation of new races?
Contrary to the opinion expressed by Darwin and others, de Vries
("Mutationstheorie", Vol. I. pages 412 et seq.) tried to show that
garden-races have been produced only from spontaneous types which occur
in a wild state or from sub-races, which the breeder has accidentally
discovered but not originated. In a small number of cases only has de
Vries adduced definite proof. On the other side we have the work of
Korschinsky (Korschinsky, "Heterogenesis und Evolution", "Flora", 1901.)
which shows that whole series of garden-races have made their appearance
only after years of cultivation. In the majority of races we are
entirely ignorant of their origin.

It is, however, a fact that if a plant is removed from natural
conditions into cultivation, a well-marked variation occurs. The
well-known plant-breeder L. de Vilmorin (L. de Vilmorin, "Notices sur
l'amelioration des plantes", Paris, 1886, page 36.), speaking from his
own experience, states that a plant is induced to "affoler," that is
to exhibit all possible variations from which the breeder may make a
further selection only after cultivation for several generations. The
effect of cultivation was particularly striking in Veronica chamaedrys
(Klebs, "Kunstliche Metamorphosen", Stuttgart, 1906, page 152.) which,
in spite of its wide distribution in nature, varies very little. After a
few years of cultivation this "good" and constant species becomes highly
variable. The specimens on which the experiments were made were three
modified inflorescence cuttings, the parent-plants of which certainly
exhibited no striking abnormalities. In a short time many hitherto
latent potentialities became apparent, so that characters, never
previously observed, or a