On the Prevention of Curl and Dry-Rot in Potatoes. 1 7 1 
form and mature its seed. This is readily observable in the case 
of weeds. The same species of grass which is common in our 
meadows will be frequently found growing by a roadside, or even 
on a gravel walk, and in dry weather will flower and bear seed, 
tliough so stunted and dwarfish as scarcely to be recognizable. 
This will occur considerably earlier in the season than the time 
of ripening of the same species of grass in an ordinary meadow, 
and again the meadow-grown plant will ripen far before another 
of the same species grown by a ditchside or in other moist rich 
soil, and this last will as much exceed the meadow plant in size 
and luxuriance as the one in the meadow did the one on the gravel 
walk. The Poa annua is a species of grass which may frequently 
be found in all the three situations above named. That potatoes 
are not exempt from this law of nature I have had abundant 
proof. On the occasion previously mentioned, where I planted 
potatoes on a piece of rich old turf, soaked for years with the 
drainage of a farm-yard, they never did ripen, but grew on 
through the whole autumn, and were as green and vigorous in 
November as they had been in July. At last a heavy fall of 
snow came with a severe frost, and in forty-eight hours they were 
as black as if they had been burnt, but the tubers were still 
thoroughly unripe, and were the very worst on the table, and 
made the best sets that I have ever possessed. In 1844 I had 
also a strong instance. In reclaiming an old lane some parts had 
to be lowered and some hollows to be filled up, and both being 
planted with potatoes at the same time, those planted where the 
old hollows had been, and which now had a considerable depth of 
fresh soil, grew considerably taller and ripened some weeks later 
than those on the ridges whence the soil had been taken ; though 
even in these places considerable pains were taken to retain as 
much of the surface soil as possible : and as the ridges and de- 
pressions ran parallel to each other for forty or fifty yards 
together, the marked difference in the time of ripening caught 
the eye at once. I have also frequently observed that potatoes 
j)lanted near hedgerow trees (especially ash) ripen earlier than 
the rest of the field. This can only arise from the abstraction of 
manure by the roots of the ash, which are fibrous and run near the 
surface. It thus appears, as well by the analogy of other plants 
as by direct observation of the potato itself, that a deficiency of 
nutriment produces early maturity, and vice versa. Fresh soil, it 
will at once be admitted, contains an extra supply of food ; 
potatoes, therefore, grown on such soil will be in a growing state 
when those on old-going land will be quite ripe, and if harvested 
together the former will be unrij)e and make good sets. It is 
very probable, however, that the more abundant supply of all the 
elements of nutrition to be found in fresh soil may have a con- 
