The weekly miner. [volume] (Butte, Mont.) 1878-1881, 1879-07-01

Nrr0un3tfm0 70 N4ne&& aA UIso ~ MeSAA
~ plantations "a II 3cct tSAhe del reda-
ts,s Of aiHhies d rata that iaslae fFos1 the
dG5Fests ~ consuane sxsrythis5Ss edithifslFthat1
comes In their way. During . recent excnr-
sion in the Province of Parana Mr.. Derby
found an almost universal lack Of corn
throughout the Province, due to such inva-
sion Of rats, by which almost the entire crop
of last year had been destroyed. This ihvat
sion, or plague as IL is called. is said to- occur
at intervals Of about 80 years, and TO be sim
Infamous with the drying Of the t~dHqaara,
or bamboo, which everywhere >abounds IN
the Brazilian forests. The popular explana-
ton is that eyery cane of bamboo sprouts
with 3 grub, the germ Of . rat, within it, and
that when the bamboo ripehs and dies the
germ becomes q fnlly-deyeloped, rat, aud
comes out to prey on the Plantations. An,
educated afd 'observant Englishman, MFR.
Herbert NJ. Mercer, who has resided a num-
Der Of years in tile Province and had an OPP
portunity of studying the phenomenon, fur
nished Mr.. Derby the following rational and
curious explanation: The bamboo arrives
at maturity, flowers and seeds at intervals of
several years, which doubtless vary with the
different species. The period for the species
most abundant in Parana is 80 years. The
process, instead Of being Simultaneous, occu-
pies about five years, a few OF the canes going
to seed the first year, an increased number
the second, and so on progressively, till finally
the remaining n dlarger portion Of the canes
seed at the same time. Each cane bears
about a peck of edible seed, resembling rice,
which is very fat and nourishing, and is often
eaten by the Indians. The quality produced
is enormous, and large areas are often COW
cred to the depth of five or six inches. After
seeding, the cane dies, breaks off at the root,
and falls to the ground, the process of decay
being fastened by the borings OF larva which
upon the bamboo and appear to be particu-
larly abundant at seeding time. These larva
have doubtless given rise to the story of the
grub developing into a rat. New canes spring
up from the seed, but require seven or eight
years to become fit for use, and thirty to
reach maturity. With the sudden and con-
stantly increasing supply of nourishing food
for a period OF five years, the rats and mice,
both of native and imported species, increase
extraordinarily in numbers. The fecundlty
of these animals is well known, and the re-
suit after four Or FIVE years Of an unusual aud
constantly increasing supply Of excellent
food, and in the absence Of eniInies Of equal
fecundity, eau readily be imagined. The last
Of the crop Of seed being matured and fallen
to the ground, the first rain causes it to decay
in the space Of a very few days. The rats,
suddenly deprived Of food, commence to mi
CRATE, invading the plantations and houses,
and consuming everything that does hot hap
pento be repugnant to the not very fastidi-
,ous. palate Of a furnishing rodent. If this
happens at the time of complaining, the
seed is consumed as fast as ii can be put into
the ground. The mandioca is dug up; the
rice crop, if it happens to be newly sown OF
in seed, is consumed, as is also everything in
the houses in the way of provisions and
leather, if not carefully guarded in tin trunks
-Ndture. aas .. .a7 ...r, .