644 SOME OF THE POSSIBILITIES OF ECONOMIC BOTANY. 
cautious as to what plants I might suggest for introduction from their 
country into our own. My good friends insisted that it was bad 
enough to have as pests the plants which come in without our planning 
or choice, and this caution seems to me one which should not be 
forgotten. 
It would take us too far from our path to inquire what can be the 
possible reasons for such increase of vigor and fertility in plants which 
are transferred to a new home. We should have to examine all the 
suggestions which have been made, such as fresh soil, new skies, 
more efficient animal friends or less destructive enemies. We should 
be obliged also to see whether the possible wearing out of the energy 
of some of these plants after atime might not be attributable to the 
decadence of vigor through uninterrupted bud propagation, and we 
should have to allude to many other questions allied to these. But for 
this time fails. 
Lack of time also renders it impossible to deal with the questions 
which attach themselves to our main question, especially as to the 
limits of effeet which cultivation may produce. We can not touch the 
problem of inheritance of acquired peculiarities, or the manner in which 
cultivation predisposes the plant to innumerable modifications. Two 
of these modifications may be mentioned in passing, because they serve 
to exemplify the practical character of our subject. 
Cultivation brings about in plants very curious morphological 
changes. For example, in the case of a well-known vegetable, the num- 
ber of metamorphosed type leaves forming the ovary is two, and yet 
under cultivation the number increases irregularly until the full num- 
ber of units in the type of the flower is reached. Prof. Bailey, of Cor- 
nell, has called attention to some further interesting changes in the 
tomato, but the one mentioned suffices to illustrate the direction of 
variation which plants under cultivation are apt to take. Monstrosi- 
ties are very apt to oceur in cultivated plants, and under certain condi- 
tions may be perpetuated in succeeding generations, thus widening the 
field from which utilizable plants may be taken. 
Another case of change produced by cultivation is likewise as yet 
wholly unexplained, although much studied, namely, the mutual inter- 
action of scion and stock in grafting, budding, and the like. It is 
probable that a further investigation of this subject may yet throw 
light on new possibilities in plants. 
We have now arrived at the most practical question of all, namely, 
In what way can the range of commercial botany be extended? In 
what manner or by what means can the introduction of new species be 
hastened? 
It is possible that some of you are aware of the great amount of 
unco-ordinated work which has been done and is now in hand in the 
direction of bringing in new plants, 
