hronicle_ for 1848, p. 862, Mr. J.B. Pentland stated
that the Ullucus "is planted in July or August, the seed employed being
generally the smaller tubers, unfit for food, and is gathered in during
the last week of April. These two periods of the year are the spring and
autumn in the southern hemisphere. The mode of cultivation is in drills,
into which the root is dropped, with a little manure. The climate, even
during the summer season, is severe, scarcely a night passing over
without the streams being frozen over, the sky being in general cloudless
at all periods of the year except during the rainy season (December to
March). Mean temperature about 49 deg.." This information seems to support
the view formed of this plant from its behavior at Kew last year, namely,
that the tubers are formed on the approach of cold weather, and that, so
long as the weather is warm and bright, leaves only are developed. Plants
grown in houses where the temperature has not been allowed to fall below
50 deg. in winter did not form any tubers, although they were in good health.
We found no tubers on the plants grown out of doors till some time after
the return of cold, wet weather. It seems likely that this plant does not
develop tubers unless its existence is threatened by cold; at all events,
such a conclusion seems reasonable from the above statements.

Possibly a wet and rather cold autumn would be favorable to this plant
and the production of its tubers--such a season, for instance, as would
be most unfavorable for the common potato. It would be worth while
testing the Ullucus for low and cold situations where the potato would
not thrive. There is not much probability of the former ever proving a
substitute for or even a rival to the potato, at least in this country;
but there is room for another good esculent, and the Ullucus is prolific
enough, hardy enough, and, we suppose, when properly grown, palatable
enough to be worthy a trial. In the _Gardeners' Chronicle_ for 1848, p.
828, will be found a most interesting detailed account of experiments
made with this plant in France by M. Louis Vilmorin.--_W. Waston, Kew;
The Gardeners' Chronicle_.

* * * * *

A catalogue, containing brief notices of many important scientific papers
heretofore published in the SUPPLEMENT, may be had gratis at this office.

* * * * *

THE SCIENTIFIC AMERICAN SUPPLEMENT.

PUBLISHED WEEKLY.