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become barren in the third or fourth generation, others afford seeds as 
abundantly as cross-bred plants. 
The principal objects of cross-breeding are, to add vigor and hardiness 
to the constitution ; to modify or get rid of defects, and to combine many 
good properties in one individual, in the shortest time. A most impor¬ 
tant point in selecting plants to breed from is, that they be hardy, adapt¬ 
ed to the climate and free from disease. The certainty of the produce 
and consequently the profit to be derived from our crops, depends much 
on their hardiness ; and there are many facts on record which seem to in¬ 
dicate that disease is hereditary in the vegetable as it is in the animal 
kingdom. 
O 
Varieties of plants which culture has much altered from the normal 
condition of the species, are not alike in all particulars. Owing to some 
peculiarity of constitution, some are better adapted to one soil or climate 
than to another, and those suited to a given location are found to possess 
different degress of excellence. These, then, constitute the materials 
with which the cross-breeder or improver has to work; and it is highly 
desirable, if not requisite, that he be well acquainted with his materials; 
he should know what has already been done, and be able to determine 
what remains to be accomplished; and what varieties of the plant he 
wishes to improve, are best calculated to further his views. It is advisable 
to consider well at the outset what constitutes perfection ; the improver 
should study his subject point by point, put his thoughts on paper, and 
to this ideal standard of perfection constantly aim. 
The practiced experimenter having thus a distinct object in view, a cer¬ 
tain standard of excellence to aim at, will carefully examine his plants, 
not with a view to select one, but several; he notes their power to with¬ 
stand adverse weather; their habit of growth; the character of their fo¬ 
liage ; the abundance, form, substance, color, size and fragrance of their 
flowers ; or the quantity, quality, size and beauty of their fruit, and the 
time it arrives at maturity. If he finds a plant having one good point in 
perfection, and not remarkably defective otherwise, it is suited to bis pur¬ 
pose ; he may cross this with another plant having a second good point, 
.and tolerably good in other respects, and may thus combine the two good 
properties in one individual. But if he could only meet with plants pos¬ 
sessing these two good points, which had also marked defects, providing 
