The Potatoe Plague. 67 
frequently asserted by the authorities, namely, “that curl ds 
sure to increase, and that curled sets are to be avoided like the 
plague.” The explanation of the rule and of this exception 
to it, appears to me to be as follows: 
Curled potatoes ripen early, some weeks before the healthy 
plants, and consequently are almost always too ripe, when 
taken up, to make good sets, and if so used the disease will 
rapidly increase each successive season. 
In this instance, however, the infected potatoes were taken 
up before they were ripe, and proved tc be as good sets as 
eould be used. The potatoes above-mentioned were taken 
up the second week in November, 1841. Having been 
planted go late the round reds were not ripe; the black kid- 
neys, a much earlier variety, were. 
1842. The same potatoes were used for seed this year. 
The unripe reds produced an excellent crop, without, so far 
as I am aware, a single failing plant. The ripe black kid- 
neys were again a failing crop. In the middle of May I 
planted, with these black kidneys, a small piece of old grass 
land, as’a preparation for forest trees. This plot of ground 
had been from time immemorial flowed over by the waste 
water from an old and ill-constructed farm yard, immediately 
adjoining, and was therefore as rich as could well be im- 
agined. The potatoes had immense tops, but very small tu- 
bers; and, when boiled, the favorite black kidneys seemed 
quite to have changed their character. Instead of the fine 
mealiness for which they are remarkable, they now bore 
miuch resemblance to a piece of yellow soap. They also 
continued growing till the frost and snow made if dangerous 
to leave them any longer in the ground, and they were taken 
up still thoroughly unripe. The round reds, grown on old- 
going land, were taken up ordinarily ripe, and were mealy 
and good. 
1843. These two kinds were again used for seed, and 
