18 THE PEARS OF NEW YORK 
1765-1842, was a pharmacist, physicist, and physician, one of the savants 
of his time, who, late in the eighteenth century, under the potent spell cast 
by Hardenpont’s work, began to breed pears. Space forbids an account of 
Van Mons’ experiments. Suffice to say that he introduced more than two 
scores of pears having lasting merit, and that in the height of his career 
he had in his ‘‘ Nursery of Fidelity’ at Louvain, eighty thousand seedlings. 
Van Mons outlives in fame the Belgian pear-breeders of his time because 
he propounded a theory for the origination of new varieties of plants, and 
this in its turn is famed as the first complete system of plant improvement. 
Van Mons contributed but little of direct value to plant-breeding, but indi- 
rectly he gave a great impetus to breeding pears and to the culture of the 
pear, more especially in America, and we must therefore glance at his theory 
and trace more in detail its influence on American pear-growing. 
Van Mons’ theory, in brief, as expounded in various papers, is: A 
species does not vary in the place in which it is born; it reproduces only 
plants which resemble itself. The causes of variation are changes in soil, 
climate, or temperature. Whenever a species produces one or many 
varieties, these varieties continue to vary always. The source of all varia- 
tion, which is transmissible by sowing, resides in the seeds. The older a 
variety, the less the seedlings vary, and the more they tend to return toward 
the primitive form, without being able ever to reach that state; the younger 
or newer the variety, the more the seedlings vary. 
In putting his theory in practice Van Mons took the first seeds from 
wild plants or those little improved, from which he grew seedlings, and 
from these the seeds were taken from the first fruits to ripen for new sowings. 
This practice he repeated generation after generation. Thus, it is seen 
that Van Mons was an early apostle of selection. He is said to have 
distributed over 400 varieties, about 40 of which are still under cultivation. 
It is to be feared, however, that Van Mons’ theory was preconceived with- 
out experiment or even observation for a foundation. He devoted a life 
of most admirable zeal to verifying and developing this vision of his early 
years with some material reward it is true, but with a better foundation 
his prodigious labors would have yielded greater direct results in improving 
the pear. Still, the indirect results, his influence on the pomologists of 
two continents, even though they did not subscribe to his theories, was 
more valuable than the work of one mind and one pair of hands could 
possibly have been. 
There must always be pioneers, men who stray from beaten paths, 
