Jan. J, 1902.] 
tHE TROPICAL AGRICtJLTUKIST. 
451 
Tunic Hemsl.— The hule macho (not Machado, ae 
M'-. PoissoQ writes it), or hule Colorado of the Coa- 
tadcans. Macho means male. Tunu, and in some 
cases tanu, is the Mosquito name of this species. 
This is not the place to discuss the value of the 
three first species, which are distinguished one from 
another by characters drawn from the carpels and 
other parts of the organs of fructification. We will 
say but one thing, aad that is that all the specimens 
of Hule gathered during the botanic ■ xplorations 
of the Jr'hysico-ffeographic Institute, directed by us in 
1888, correspond with the description given by Lieb- 
mann of his Castilloa Costaricana. This certainly 
does not exclude the presence in the country 
of the Castilloa, elastica, Cetv, which besides 
cannot well differ specifically from the foregoing ; 
if this last hypothesis is not confirmed, the presence 
in Costa Rica of the species of Cervautes remains 
yet to be proved. We will say the same of the C. 
Marhhamiana, a species equally doabtfal and to be 
studied anew. 
Castilloa Tunu, Hemsley, — As for Castilloa Tunu, 
it is a species absolutely distinct from the foregoing, 
described recently by Mr. Hemsley, if we miscake 
not, from samples collected by us personally, in 
March 1898, in the valley of the Diquis, on the 
aouth-western slope of Costa Rica, and distributed 
by the Phyaico-geographio Institute under the No, 
12,051. The original label, accompanying the examples 
from the National Herbarium of Costa Rica, saya 
they come " from a tree abounding by groups in the 
region of Diquis, attaining a height of 8 to 12 metrei, 
and distinct at first sight from other Castilloas by 
its coriaceous, glabrous, sharply entire leaves, and 
by its female receptacles being very small, and flanked 
by seeds of which the glabrous envelope shews from 
three to six sutures keeled." Among the specimeua 
now before us, there is one bearing three cupulea 
with seeds, answering to the description above, with 
a solitary male receptacle near the end of the 
branch; two other pieces of branch only present 
male flowers of which ihe receptacles seem mostly 
twin, as in the other species. 
Lastly, we are in a position to state that Mr. 
Eugene Poisbon, to whom we have made a present 
of a part of the samples mentioned above, has taken 
away from here neither the milk nor the odoutchouc 
of the Castilloa Tantt. There has simply been a 
lamentable confusion of names and specimens. The 
milk carried away by Mr. Eugene Poisson, drawn 
by us together, is that of the hule proper Costa- 
ricana), at "La Pepilla" ; the specimen of gum of 
which Mr. Godefroy Lebeuf speaks, was extracted 
from our own gatherings, and from the same speciea 
■ in the plains of Santa Clara. Some botanical speci- 
mens, of which Mr. Poisson has taken away a por- 
tion while the rest figures in our herbarium and 
has been distributed under the number 13,429, were 
gathered at the same time and place as the milk, 
and can in no way be oonfoanded with the Cctstilloa 
Tunu. 
The latter, which has not been reported with 
certainty until now ou the Atlantic side of Costa 
Rica, gives, it ia true, an abundant milk, but the 
rubber drawn from it gets brittle and falls to powder 
in a very short time. In the New York market it 
ia aaid to have been quoted, a few years ago, at 
from 12 to 14 centa, a price so unprofitable that the 
exploitation of this species haa been completely 
abandoned. 
Opinion on the species noted by Mr. Koschny. — Aa 
for the new specioa or varietiea of Mr. Koschny, I 
cannot make up my mind to give them i botanio 
value ; the distinction through the colour of the 
bark, by which he is guided, ia insufiBcient. 
I am convinced that we have here to deal with 
no more than individual difierences, the result of 
immediate eavironment and changing with its 
conditions, 
i (Sigued) H. Phhee, 
\_Note by tht Editor. We must bear in mind that 
Mr, Koschny has taken care to send herbarium 
specimens to Berlin ; the only thing to be done is 
to await quietly the decision of the botanists charged 
with their examination.] 
APROPOS OF THE ARTICLE : "GOOD AND 
BAD CASTILLOA." 
(A letter from Mr. Koschny.) 
Mr. Koschny, who is one of the oldest colonists of 
San-Carlos in Costa-Rica, like all educated Germans, 
reads French, but is not well enough acquainted 
with it to write articles in that language ; his letter 
ia therefore written in German ; we will summarise 
its contents. 
USELESSNBSS OF THE GUM OF THE TANU. — Mr. Kos- 
chny maintains that the latex of tha 
Mr. Koschny Tanu only furnishes a hard gum, brit- 
adheres to this tie and devoid of elasticity ; he ia 
pronunciation, convinced that his Tanu ia really the 
contrary to Mr. Castilloa Tunu, Hemslet. Letua leave 
Pittier, who the professional botanists to settle this 
writes "Tunu." point after comparison of the herba- 
rium specimens. 
The Tanu, Mr. Koschny writes to us, is abundantly 
represented on the Mosquito Coast, but it exists alao 
on the Pacific. The name ia reserved expressly for 
the trees of which the gum is brittle. The reputa- 
tion of this gum ia so atrocious that the mer- 
chants of New York refuse the "Sheet Rubber" 
of Nicaragua in apite of its cleanneas and careful 
preparation ; and this is simply from fear of coming 
upon goods falsified by the latex of the Tanu, In- 
deed the preparation of the sheets makes this falai- 
fication possible, while it cannot be effected in tb« 
case of "scrap" (Castilloa caoutchouc coagulated 
apontaneoualy on the trunk itself or at the foot of 
the tree.) 
Everyone in this country, saya Mr. Koschny, 
knows the evil repute of Tanu gum ; the French 
Consuls at Panama and Bluefielda can, if necesaary, 
certify to the fact. 
We sincerely thank Mr. Koschny for having given 
himself the trouble to pick out what appeared to 
him inexact in our article of July, We hope he 
will do BO again whenever he meets with, in the 
Journal d' Agriculture Tropicale, any question falling 
within his competence. We have no preconceived 
opinions whatever, and far from evading discussion 
we invite it, so long as it keeps inaide the field 
of fact. 
INDUSTRIAL USES OP TUNU ACCORDIlJa 
TO MR. PEARSON. 
What Mr, Koschny saya of the stuff known in 
commerce under the name of Tunu, is quite in 
accordance with the information to be read in the 
volume "Crude Rubber and Compounding ingredients " 
of Mr. Pearson, Editor of the India BvMer \Vorld, the 
great New York caoutchouc review; here ia the text 
in question: — 
" Tuno, Toonu or Tunu, ia a name of un- 
certain origin, applied in commerce to designate a 
caoutchouc gathered chiefly in Nicaragua and Hon- 
duras. ... Its coagulation ia effected by heat. 
The rubber obtained has but little elasticity ; it be- 
comes very fishy when heated ; its selling price is 
low. It ia used in the making of pencil erasera, 
and, mixed with balata, in the manufacture of driv' 
ing belta. 
" Sometimes thia rubber ia aold under the name 
of " Seiba Gum," after it haa been made to loie 
ita natural appearance by a laborious aoaking under 
water. The true caoutchouc of Nicaragua ia some* 
times adulterated by the addition of Tunu, just at 
the moment of coagulation ; this mixture makes the 
rubber lose in a short time its suppleness and it| 
industrial (jualitias." 
