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THE TROPICAL AGRICULTURIST. 



[August i, 1883. 



As regards details of generic and specific liniitatiou, of 

 course, no two authors who work independently, but will 

 vary considerably. In the matter of fern-genera, system- 

 atists are divided into two parties — one regarding a ditfcrcuce 

 in veiuing as sullicient m itself to found a genus upon, 

 aad the other maintaining substantially intact the time- 

 honoured geuent, of .Swartz and WillUenow, which are 

 fouuded entirely on characters derived from fructification. 

 Of the first party among modern writers, Presl, Fee, 

 Smith and Moore, aie the leading representatives, of the 

 lutter, Hooker, Mettenius and fiaton. Upon this matter 

 1 differ from Ool. Beddome, and the difference amounts 

 to wishing to use different names for perhaps half the 

 species included in his book. Of com-se, what he and Mr. 

 Clarke have written about species-limitation and the dis- 

 tribution of the species thi'ough different parts of India 

 will be a great accession to our knowledge ; but I am 

 rather amused to see that out of the Hmited number of 

 new species which Mr. Clarke made, he refuses to admit 

 at least half ; and that lie totally rejects the only material 

 innovatlou that Mr. Clarke proposed on the classification 

 of GUI- " Synopsis FiUcum," the dividing of our Asjytenitim 

 xivihrosuiii, to establish out of part of it anew section of 

 Asplenium, to be called PseudaUautodia, and characterized 

 by a sausage-shaped involucre bursting irregularly. , The 

 only points on which I feel inclined to find fault with 

 him are two. The first, that in his key to the genera he 

 puts Hymi uophyllese under Polypodiacese, witliout taking 

 any notice of the difference in the structure of the spor- 

 ange, - but I see this is noticed in the detailed diagnosis 

 at p. 28. It seems to me that Hymenophj^lle^ have ex- 

 cellent claims to be regardetl as a distinct sub-order. The 

 other point on which I wish to euter a decided objection 

 is to the plan which he follows, or rather want of plan, 

 in citing the authorities for the specific names. \A^heu 

 he places a species under a different genus to that under 

 which it was classified by its original describer, he moves 

 backwards and forwards without any uniformity between 

 four different ways of citing the authority. Sometimes he 

 writes " Gleichenia t/lauca (Hook.) " for a plant described 

 by Thunberg as l^oiypodmm ylaucum, aad transferred by 

 Hooker to (a-leicheaia; which is the plan usually adopted 

 by botanists. But in many other cases he writes " , Botry- 

 ckiu'H Lunnyia (Linn, under Osmunda)" when the species 

 was described by Linnaeus as an Osmunda and trans- 

 ferred by Swartz to Botrychium ; or " Cyrtomium falc- 

 atum (Sw.) " when Swartz called the plant A^pidinm Julc- 

 atum and Presl transferred it to Cyrtomium ; or even 

 " Lasirea theh/pteris (Desv.) " for a plant published first 

 by Linnaeus as a Polypodium, transferred by Swartz to 

 Aspidium, l>j Dcsv^ai^x to Nephrodium, and Presl to Lastrea. 

 And the same uncertainty vitiates his citations of books 

 at t^e end of his descriptions. His citations refer to the 

 phtnt, but according to the accepted usage amongst botanists 

 ihey will he taken, and very often wrongly taken as re- 

 ferring to the binomial name as used, so that if anyone 

 copies synonymy from the book without checking it off 

 he will often find it leads him astray. J. G. Baker. 

 — Nature, 



REPORT ON SOME OF THE INDIARUBBER 

 AND GUTTAPERCHA TREES OF GUIANA. 



BY THE GOVERNMENT BOTANIST, MR. G. S. JENMAN. 



On the pubhcation in Timehri-, the Journal of the Royal 

 Agricultural and Commercial Society of British Guiana, 

 of my report to (Government on Hevea Sprucetina, inquiries 

 were adilressed to me by persons interested in the matter 

 for more specific information than that report contained 

 as to the yield of this newly-found species of Hevea, the 

 age at which it might profitably be tapped for its juice, 

 and the nature of the land best suited for its growth 

 under cultivation. These were subjects which the time at 

 ray disposal only permitted me to investigate partially on 

 my former journey, and on the receipt of the applications 

 alluded to above, I dcemeil it important that, as far as 

 possible, the information should be obtained. As soon, 

 therefore, as I had the time to spare after my retm'u 

 from England in September, I obtained the approval of 

 ids Escellency the Governor of my design, and permission 

 to visit the interior to acquire by personal ob.servation and 

 experiment the objects stated. 



The journey which was the subject-matter of my former 

 report on this species of Hevea was made on the Essequibo 

 and Mazaruni rivers, where in certain creeks, and in 

 scattered and often distant localities on the banks of the 

 main rivers, I found, by my own investigation, and by 

 inquiry of the Indians and other residents, the tree to 

 prevail in more or less abumtance. This being so, it 

 appeared to me that, on this occasion, while carrying out 

 the primary objects of my mission, I might make further 

 acquaintance with its thstribution; to accomphsh which in 

 the best way, I deemed it would be advisable not to return 

 to the rivers with which I was already acquainted, but to 

 visit another part of the country. It was necessary, how- 

 ever, to determine in advance that the region I might decide 

 to take was not destitute of this tree; and finding, on 

 inquiry, I could accompUsh my object on - the Pomeroon 

 river, which flows through a region that was hitherto un- 

 known to me, and divided by a wide tract of country from 

 the rivers I have mentioned, I took this river for my 

 operations. Mr. im Thurn, the Special Magistrate of the 

 district, was good enough to ascertain for my assistance 

 the situation of some of the best locahties, to save me any 

 delay in seeking this information on my arrival, and I 

 may here acknowledge the material assi.«tance I derived 

 from him ia this and other ways. Indeed without his aid 

 I should have found my movements very ditficuit at times, 

 with the sparse population of the region and under the 

 bad weather which I, unfortunately, experienced. 



To make the information in this report intedigible to 

 readers who may not have the former one to refer to, 

 it will be necessary as I proceed to touch occasionally on 

 matter which that contained; and in this connection I 

 may mention that the Indian* names of Hevea Sprvceana — 

 taking the tribes whi inhabit the belt of country in which 

 its distribution is principally embraced — are, Jrawack, 

 Hatie: — Curibisi, Poomui: — Ackawoi, Sibi-sihij of which the 

 Araimck name is the most generally known by the river 

 residents, and that it is a tree very similar in general 

 appearance to Hevea brasiliensis whicn yields the valuable 

 Para rubber, and which is at present the most impoi tant 

 of the caoutchouc trees worked for market. Both trees 

 attain about the same dimensions, and appear to grow 

 under preciselv the same conditions. Indeed tUe description 

 of the ground on the Amazon given by the collector Cross, 

 would apply literally to the groun-l on the rivers of this 

 colony occupied by H. S'pruceana. 



At this time of year (December), which is the height 

 of the winter rainy season, the laud is partially flooded, 

 but the cessation of rain for a few days together makes 

 a great dift'erence in the quantity found diffused over it. 

 The water lies in shallow pools between the trees, or is 

 spread in sheets, when deeper, over wide spaces of ground, 

 and the sm-f ace-soil generaUy, especially where this tiee 

 most abounds, is hardly more firm or dense than mud. 

 It will give an idea of its character when I say that I 

 wore a pair of high laced-up shootmg boots, but with the 

 best care in moving about, and stepi>ing mostly on the more 

 solid soil which is usually f.)imd in hillocks around the 

 butts of trees, or on the fallen bits of wood which stretch 

 between them, in spite of my care, I was coustantly sink- 

 ing to their tops and over, so that my .socks were coated 

 with mud. I am sp, aking. as I have said, of the wet 

 season of the year, but even in the dry, the ground 

 continues in a very moist condition. The land is usually 

 very densely shaded, and in many p'aces, probably in 

 con.sequence, produces very little underg.owth. It appears 

 probable that ground such as I have described is essential 

 to the best development of Hevea, as where these con- 

 ditions most uniformly prevail in the locahties where it 

 IS found, there most of the trees occm-; and to this cir- 

 cumstance I am disposed to ascribe its greater prevalence 

 on the creeks than on the main rivers. On the latter 

 the banks are rather higher than they are on the former 

 and in many instances higher than the land within them, 

 The surface drainage uf the country is in the first instance 

 into the creeks, and ttu ir banks are intersected with numerous 

 and near channels. — ;i feature which the banks of the 



* "Indian": of course natives of South America are in 

 every case meant. I'liat the term ** Indian" should still 

 attach to these people* is only a lesser l)lunder than that 

 of naming the western worUl, which Oolumbus discovered 

 America — Ed.] 



