ACCLIMATATION. 25 
‘duced were weak, slender, not half so tall as those of the 
first generation, and grew in the shallowest water only. The 
seeds of these plants produced others the next year, sensibly 
stronger than their parents of the second year. In this 
manner the plants proceeded, springing up every year from 
the seeds of the preceding one, every year becoming visibly 
stronger and larger, and rising from the deeper parts of the 
pond, till the last year, 1801, when several of the plants were 
six feet in height,and the whole pond was in every part covered 
with them as thick as wheat grows in a well-managed field.” 
Respecting this experiment Dr. Lindley, who was no believer 
in the doctrine of acclimatation, says, “It is to be remarked 
that in the very first year this Canada rice grew as vigorously 
as afterwards ; that its first progeny was feeble, that it only 
recovered its vigour after it had been reproduced often 
enough to establish itself in the deeper parts of the pond, 
and that at last, after many generations, it was only as vigor- 
ous as at first. The case was not one of naturalization, but 
of deterioration succeeded by restoration, not improvement. 
Many reasons might be assigned for the temporary deteriora- 
tion; but that the plant was not naturalized is sufficiently 
proved by its having disappeared long since.” And he adds: 
“Dr. Macculloch, who ably advocated the doctrine of acclima- 
tation, rested his case upon two grounds ; the one, that many 
sickly greenhouse plants acquired great vigour in Guernsey 
when turned into the open air, and that seedling guavas were 
productive there, although their parent was sterile; and the 
other, that hardy varieties of the vine, the pear, and other 
fruits, are well known to all cultivators. But this reasoning 
was unsound; Dr. Macculloch did not show that the greenhouse 
plants in question had become more hardy than they were be- 
fore ; it only happened that they became more healthy ; and 
in regard to the so-called hardy fruits thus alluded to, there is 
nothing to show that their constitutions are at all hardier than 
those of their parents; what is called hardiness in these 
species consisting in an alteration in their time of flowering or 
fruiting. 
