i74 



NA TURE 



{Dec. 23, i! 



vegetable products of the Perso-Afghan region which are 

 articles of commerce with India and other countries. 

 Much uncertainty existed respecting the plants yielding 

 some of these drugs, dyes, and other substances, and no 

 m^re welcome contribution to botanical knowledge could 

 be made than the removal of this uncertainty. 



The Commission left Quettah in September 1SS4, 

 taking a south-westerly direction as far as Nushki, and 

 thence the course was north-westward across Northern 

 Baluchistan to the Helmund River, which was touched 

 in about 63' E. long. This section of the journey pro- 

 duced little, as the country is very barren and the season in 

 which it was traversed the worst of the year forbotanising. 

 Nevertheless a few interesting things were picked up, 

 notably ripe fruit and seeds of Stocksia bra/mica, which 

 were previously unknown. The fruit, or seed-vessel, is 

 an inflated capsule, similar to that of the Chinese Koel- 

 j-ciitL-ria, near which Slocksia is placed, and so brighth' 

 coloured that it bears a name equivalent to " mountain 

 peach." 



That part of the journey from the Helmund northward 

 to Kuhsan, a little to the north-west of Herat, was accom- 

 plished at the rate of twenty miles a day, therefore there 

 was little opportunity for collecting. Indeed the fatigue 

 attending the travelling was so great that frequent dis- 

 mounting to secure specimens of natural history was out 

 of the question In spite, however, of all drawbacks and 

 difficulties, specimens of about one hundred species of 

 plants were dried ; and this collection was despatched to 

 India, by way of Herat and Candahar, where it arrived 

 in a rotten condition, having apparently been iinmersed, 

 probably in crossing some stream, during the transit. 

 The small collection made in Baluchistan had in the 

 meantime reached Kew safely. 



The main collection of dried plants, consisting of about 

 800 species in 10,000 specimens, was made in an irregular 

 tract of country lying between about 59" and 64" of longi- 

 tude and 34° and 37° of latitude, with Herat near the 

 south-eastern, and Meshed near the north-western limits. 

 This collection was the result of one year's work ; yet it 

 by no means represents the entire flora of the area in 

 question, partly in consequence of the difficulties attend- 

 ing the daily transport of collections constantly increas- 

 ing in weight and size, and partly on account of the 

 necessity for keeping with the main party. These con- 

 tingencies, rather than the resources of the country, de- 

 termined the e-Ktent of the collection Thus, for instance. 

 Dr. Ailchison rarely reached an altitude of more than 

 5000 feet, so that he collected no portion of the vegeta- 

 tion of the upper zone of the country. However, as the 

 mountain flora is of more purely botanical interest, while 

 that of the plains is of special commercial importance, on 

 account of the number of economic plants it contains, its 

 absence is, from the economic point of view, the less to be 

 regretted. 



At present the collection has not been fully worked out ; 

 but it is estimated that it comprises about a hundred 

 species previously unknown to science, besides largely 

 supplementing the material in herbaria of many obscure 

 plants. Its principal value, however, as already men- 

 tioned, lies in the number of usually Aery complete speci- 

 mens of economic plants and their products. 



Foremost in importance, and the characteristic and 

 dominating feature of the vegetation of the plains, are the 

 Uinbellifera. Some of these are of gigantic size, for 

 herbs, and several of them yield valuable gum-resins, 

 known in commerce as gum ammoniacum, gum gal- 

 banum, asafoetida, &c. A special paper on these plants 

 was read by Ur. Aitchison on December S before the 

 Pharmaceutical Society, therefore it would be superfluous 

 to enter into details here. Early next year will be published 

 a full and illustrated Report on the whole collection, in 

 which prominence will be given to the economic plants : 

 such as have not previously been figured, or only in- 



adequately figured, will be selected for illustration. 

 Remarkable among the UiubcUifcru' not known to yield 

 gi m-resins are Ferula oopoda, Boissier, F. suavcolens, 

 Aitchi ion and Hemsley, and Dorcina scrndatum, Aitch- 

 ison and Hemsley. The first we have identified 

 with a described species, though the specimens are 

 very fragmentary, and the description incomplete. It 

 is a most singular plant, in which the bases of the cauline 

 leaves are developed into large circular bowls, through a 

 succession of which, gradually smaller upwards, the stem 

 passes. The largest of these bowls are as much as a foot 

 in diameter, and about two quarts in capacity. From 

 his investigations on the spot, Dr. Aitchison is of opinion 

 that these bowl-like expansions of the petioles do not 

 serve the plant as reservoirs of water : possibly they may 

 prevent the ascent of insects which infect and consume 

 the fruit of many of the Umbellifera; of the region. F. sua- 

 vcolens furnishes a kind of sambal, and the Dorema is a 

 verj- distinct new one. These Uiiibellifera; form very 

 beautiful miniature forests ; D. glabrum growing as much 

 as 10 or 12 feet high. 



Anrong other economic products whose sources have 

 been traced and good specimens of the plants secured, a 

 yellow dye, largely imported into India, may be men- 

 tioned. It is furnished by an apparently undescribed 

 species of De'pliiiiiiun. Another dyeing material turns 

 out to be the roots of a species of Pruniis {P. {Cerasiis) 

 calycosiis, Aitchison and Hemsley), remarkable in being 

 apetalous ; the petals being replaced by the coloured 

 petal-like calyx-lobes. Pislacia vera Dr. Aitchison re- 

 gards as undoubtedly indigenous in this region, and 

 numerous other interesting facts of the same nature will 

 be described in his Report. 



In conclusion, it may be mentioned that Dr. Aitchison 

 succeeded in bringing home his extensive botanical and 

 zoological collections by way of the Caspian and Black 

 Seas, in an admirable state of preservation. Of course, 

 it will be understood that there is no difficulty in drying 

 plants in Afghanistan and Persia. In fact, they are likely 

 to get too dry, and consequently break and crumble to 

 pieces in transport, especially when, as in this case, they 

 are carried on camels and mules day after day ; and it was 

 only by the most careful and elaborate packing that the 

 plants were pre\ented from being rubbed into powder. 

 W. BoTTiNG Hemsley 



DEPOSITS OF VOLCANIC DUST 



IN several recently-published papers,^ Prof. George P 

 Merrill has called attention to some interesting de- 

 posits which are shown by careful microscopic study to 

 consist of volcanic dust. 



Samples sent by Mr. Zahn, of Nebraska, to the United 

 States National Museum were supposed to be "geyserite," 

 and similar materials are said to occur in Western Kansas, 

 Eastern Colorado^ and Wyoming. They were found in 

 small patches or in beds up to four feet in thickness, 

 covered by a considerable thickness of other deposits. 

 Of this material Prof. Merrill writes as follows : — 



" A glance at the samples was sufficient to convince the 

 writer that they were not the result of geyser action, but 

 were probably of volcanic origin. One was of almost 

 chalky whiteness, very finely pulverised, and of a sharp, 

 gritty feeling w-hen rubbed between the fingers. The 

 second was gray in colour, slightly coarser, and had, even 

 to the naked eye, a flaky appearance. Submitted to micro- 

 scopic examination, both samples were found to consist 

 almost entirely of the minute particles of amorphous 

 glass, such as originate from the fine pulverisation of a 

 glassy pumice, with only occasionally a fragment of a 

 greenish mineral that was apparently hornblende." 



' " On Volcanic Dust from Soutli-Eastein Nebraska" (Proc. Nat. Mus- 

 vol. vai. 1S85. p. 99: "Notes on the C)mpositlon of Certain 'Pliocene 

 Sandstones' from Montana and Idaho" (Am Journ. Sci. vol. xxxii. iS86, 

 p. 199). 



