Jan. 1, 1902.] THE TROPICAL AGRIC17LTURIST. 
-APROPOS OP OASTILLOA TUNU 
HBM3L, AND OP OTHBR NEW 
CASTILLOAS. 
(Appeared ia the " Journal d' Agricaltnre Topi- 
cale" of Slat August 1901). 
[Editor's Note,— We draw the special attention 
of our rearlers to the letter from Mr. Eugene Poiseon, 
printed below. Mr. Poissou has been good enough 
to respond to the appeal we made, in our July 
number, to his zeal in the cause of science ; we 
are most grateful to him for it. 
With regard to the facts Mr. Poisson gives on 
the origin of his specimens of Castilloa Tumi Hemsl., 
details are so absolntelyprecise that no doubt whatever 
remains as to the difference existing between the 
bad Castilloa of Koschnt, called Ttjnu by the in- 
habitants of the valley of Sao Carlos, and the Cai- 
tilloa Tunii Hemsl. of the San Jose country and of 
British Honduras, sold by Mr. Godepeoy-Lebeuf. 
To discover what exactly the Tdnu of Koschnt 
is, we must have a little patience; the Berlin botanists 
will perhaps tell us shortly. 
The letter of Mr E. Poisson contains two other 
hints of great practical value; the first is as to 
the varieties of the Hevea hrasiliensis. On this head 
the observation of our correspondent, made at Para, 
has just found confirmation in an analogous remark 
made on the cultivated Hevea by Mr. Derry in 
the Malay Peninsula ; we will again refer to it in 
our September issue of the Journal d' Agriculture 
Tropicals. The second observation in Mr. Poisson's 
letter refers to the remarks of hin father and of 
Mr. Jules Guerin upon a Castilloa giving a fi«hy 
extract, which is met with in Guatemala. Planters 
will be indebted to Messrs Guerin and Poisson 
for letting them know of this "lioa, " for which 
the place in botany has yet to be determined, and 
they will know they have to beware ot this Cas- 
tilloa. 
Unfortunately, to be able to avoid a species, one 
must know it well, but a precise and useful des- 
cription of a plant can only be given when it has 
been duly classed in the botanical hierarchy ; and 
that, is what is now being done at the Museum 
of Natural History in the matter of the liga. (Signed 
J. Vilbouchevitch.)] 
Paris, 12th August, 1901, 
Dear Sir,— In reply to the article "Good and Bad 
Castilloa" corjtained in No. 1 of the Journal cC 
Agriculture Tropicale, in which yon are kind enough to 
mention, may I offer you the following refleotioni ; 
— The botanic and economic study of the genus 
Castilloa is far from being exhausted. This is as 
much the case for this genua of Artocarpacae »3 it 
ia for the Eeveas, of which the numerous species 
are not yet disentangled in any satisfactory manner, 
in apite of the ability and the ceaseless labours of 
■'Mr. Botting Hemsley. This savant has set himself 
to elucidate the question of the Utve ks, the Cas- 
tilloas, and the Sapiums, the three principal Ameri- 
can genera producing caoutchouc. 
Many other sorts ot plants are cited in the books 
BS yielding a utilisable latex, but » great number 
have not been studied at close q uarters ; many cal- 
culations will be upset when weil-condncted experi- 
ments have been made. 
As to what bears upon the Castilloa of Costa 
Rica, which I know a little, I have not heard Mr. 
Pittieu de Fabkega say that there are other species, 
and I myself Lave only iseen one kind of tree, the 
U. Tunu. It is possible that elsewhere, on the 
Pacific slope for instance, there may be Castilloa 
elastica and perhaps other species besides, since 
Mb Hem-ley has just published a new Castilloa 
C. australis, in Hooker's Icon, Flantar (February 
1901) of the Peruvian r»gion. 
57 
Of the Tunu I have bronght back 
(1) Branches bearing fruits tnkcu by me from the 
trees themst-Ives ; 
(2) Herbarium specimens, in Flower, given m« by 
Mb. Pittifr. These materials have been 
sent to the Museum of Natural History. 
At mv request, some fruit-bearing receptacles 
have been sent to Mr. B. Hemsley, the learned 
curator of the Kew Herbarium, wtio I knew wished 
to complete his description before the publication 
of this Castilloa, which until then had only been 
remarked in British Honduras. A little time after- 
wards, my father inserted a note in the Bulletin 
du Museum 1900, (p. 137) on this new pUnt, and 
shewed, at one of the monthly reunions held ia 
that establishment, a fine specimen ot the caoutchouc 
furnished by it. After a testing carried out by Mr 
Lamy Torrilhon, this caoutchouc was valued as first 
quality. At the same time, my father soon regretted 
having misunderstood a page of the Bulletin of 
Miscellaneous Information, of Kew (June 18JS), 
which he would have cited, and in which BIr. Hemsley 
gave the history of the C. Tunu before his publica- 
tion. Already Sir J. Hooker in (7V'i«srtc. Linnhot. 
ser., 2, II, p. 212) had spoken of this Castilloa, 
which to him appeared distinct from the C. elas- 
tica ; Mr. Bowland Cater would have confirmed 
him in this idea, but there was a doubt on tba 
point, and the uncertainty could not end until 
samples complete and in good condition could ba 
had. Thus it has required long years for a full 
knowledge of this species. If I have dwelt on this 
point, it is in order to shew what perseverance is 
necessary to clear up questions of this kind ; they 
are liable to remain indefinitely in obscurity with- 
out sustained efforts made. The geographical area 
of the C. Tunu is thus very extensive, relatively 
for it reaches from British Honduras to CostH-Rics, ; 
perhaps even going further yet to the south. We 
must not forget that in the identification of botanical 
species trouble often arises from the fact that popu- 
lar names vary from one region to another; at 
times these local names are different in one and 
the same country. Thus, in Honduras, the C. Tunu 
has two or three distinct trivial names; in Cost* 
Rica it is called ULE MACHAPO in the district 
of San Jose, and perhaps something else on the 
western slope of that State. 
As to what relates to the work of Mb. Koschnt, 
I think it ought to be taken into oonaidoration, 
but without going further until the sorts, varieties 
or species of which he speaks are clearly distin- 
gniehed botanically. It is besides quite possible 
that there may be a correlation between the abun- 
dance or the quality of the latex of these different 
castilloas anil the appreciable organographic charac- 
ters of each of them. This fact would accord 
with what I have seen in Amazonia in certaiq 
races of Hevea, mentioned in the Rtport I am 
preparing for the Minister of Public Instrnotion. 
Another interesting observation on the Castilloa, which 
I have from my father, Mr. Jules Poisson, is ai 
follows; — Mr. Jules Guerin, commisary-general for 
Guatemala at the Universal Exhibition of 1900, had 
brought herbarium specimens of two Castilloas, with 
samples of latex. One of them, recognised as bein({ 
the C elastica, gives a latex coagulable as is cus- 
tomary in that species. The second, called C. Liga, 
produces a milk which will not coagulate or gives 
a useless material. Nevertheless, the herbarium 
specimens are hardly dietinguishable by the most 
experienced observer. The Liqa has the leaves a 
little less silky, the tints a little less clear, but are 
these characters constant? One cin understand how, 
in practice, mistakes are easy, since the collectors 
mix without noticing the two latices, whence 
irreparable damage to the gathered material whan 
the labourers come upon the bad kind of Castilloa. 
The herbarium samples are unfortunately unaccom- 
panied by flowers and fruits, which perhaps would 
decide the question. We mu§t only wait until M', 
