TORREYA AND NATURE-STUDY REVIEW Special combined price $1.50 for the year 1909 This special offer is good only as long as the publishers of the above journals can supply back numbers of early 1909 issues. In no case will the subscription be extended beyond December of this year. The offer is limited to new subscribers of either journals and also is not open to members of the American Nature-Study Society, of which THE NATURE-STUDY REVIEW is the official journal free to members. By later sending 25 cents additional to the Secretary of the Society the subscription on above terms may be credited as member's fee for the American Nature Society for 1909. Correspondence relating to above special offer should be addressed to DR. WILLIAM MANSFIELD College of Pharmacy 115 W. 68th Street New York City OTHER PUBLICATIONS OF THE TORREY BOTANICAL CLUB (1) BULLETIN A monthly journal devoted to general botany, established 1870. Vol. 35 published in 1908, contained 608 pages of text and 40 full-page plates. Price $3.00 per annum. For Europe, 14 shillings. for England. Dulau & Co., 37 Soho Square, London, are agents Of former volumes, only 24-34 can be supplied entire; certain numbers of other volumes are available, but the entire stock of some numbers has been reserved for the completion of sets. Vols. 24-27 are furnished at the published price of two dollars each; Vols. 28-35 three dollars each. Single copies (30 cts.) will be furnished only when not breaking complete volumes. (2) MEMOIRS The MEMOIRS, established 1889, are published at irregular intervals. Volumes 1-11 and 13 are now completed; Nos. 1 and 2 of Vol. 12 and. No. 1 of Vol. 14 have been issued. The subscription price is fixed at $3.00 per volume in advance. The numbers can also be purchased singly. A list of titles of the individual papers and of prices will be furnished on application. (3) The Preliminary Catalogue of Anthophyta and Pteridophyta reported as growing within one hundred miles of New York, 1888. Price, $1.00. Correspondence relating to the above publications should be addressed to DR. WILLIAM MANSFIELD College of Pharmacy 115 W. 68TH STREET NEW YORK CITY THE TORREY BOTANICAL CLUB OFFICERS FOR 1909 President HENRY H. RUSBY, M.D. Vice-Presidents EDWARD S. BURGESS, PH.D. JOHN HENDLEY BARNHART, A. M., M.D. Το TORREYA is furnished to subscribers in the United States and Canada for one dollar per annum; single copies, fifteen cents. subscribers elsewhere, five shillings, or the equivalent thereof. Postal or express money orders and drafts or personal checks on New York City banks are accepted in payment, but the rules of the New York Clearing House compel the request that ten cents be added to the amount of any other local checks that may be sent. Subscriptions are received only for full volumes, beginning with the January issue. Reprints will be furnished at cost prices. Subscriptions and remittances should be sent to TREASURER, TORREY BOTANICAL CLUB, 41 North Queen St., Lancaster, Pa., or College of Pharmacy, 115 West 68th St., New York City. Matter for publication should be addressed to JEAN BROADHURST Teachers College, Columbia University Vol. 9 TORREYA September, 1909 THE RUBBER PLANTS OF MEXICO * BY H. H. RUSBY No. 9 Until within a few years, there was but a single known source of commercial rubber in the entire republic of Mexico. Now two species are contributing regular supplies, and a third, to be specially considered here, is likely soon to become a very important factor in this industry. Mexico thus becomes one of the most important of the world's rubber-producing countries. That other sources remain to be developed is very certain, since the families Euphorbiaceae, Moraceae, and Apocynaceae, which comprise most of the rubber-yielding plants, are abundantly represented in the Mexican flora. The same may be said of the Sapotaceae, the family that yields gutta percha, chicle, and balata. The first of the rubber-producing plants mentioned above is Castilla elastica, the Central American rubber tree known also as the Mexican rubber tree or "hule," in all but recent literature. So al undant is this tree in one locality, that it and its railroad station are known as El Hule. This tree also yields rubber in the West Indian Islands. It is a near relative of the Ficus, yielding the East Indian rubber, to which its product bears considerable resemblance. On the other hand, it is not related to the Hevea, which yields the superior Para or Amazon rubber. The Castilla becomes a large tree, some authors state up to six feet in diameter, and lives to a great age. Owing to the destructive methods of collecting its latex, the exportation of Mexican rubber declined from $160,000 in 1882-3 to $47,000 ten years later, and the government was faced with what threatened to be [No. 8, Vol. 9, of TORREYA, comprising pages 153-176, was issued August 3, 1909.] * Abstract of a lecture delivered before the Torrey Club, February 9, 1909. lustrated with the aid of the Catherine McManes fund. |