206 Floristik, Geographie, etc. — Agricultur, etc. 



Jura bis in die N. O. Schweiz. Diese westlichen Arten zeigen: 

 grosse Verbreitungslücken; Bevorzugung warmer Thalkessel; weit 

 abgesprengte Inselareale, (Thüringen, Blautal bei Ulm, Inseln 

 der Ostsee). Das heutige Areal dieser Arten ist „ein derart zeris- 

 senes und lückenhaftes, ganz besonders im schroffen Gegensatz zum 

 Areal der pontischen Arten, dass eine Einwanderung unter den 

 heutigen klimatischen Verhältnissen sich nicht wohl annehmen 

 lässt. Man muss daher an Einstrahlung in einer früheren und 

 wärmeren Periode als der gegenwärtigen denken." — Die westli- 

 chen Einwanderer der N. O. Schweiz lassen sich zu drei Kategorien 

 gruppieren: 1) Jurassische Arten (z.B. Bi(pleuriim longifolium und 

 falcatum, Thalictrum minus etc.); 2) Sübjurassische Arten {z.B. Hi- 

 mantoglosstim. j Aceras, Dentaria pirmata , Scilla hifolia, Sediim riibens 

 etc.); 3) Allgemein verbreitete westliche Arten (z.B. Tamus commu- 

 nis, Hex, Viola alba, Chlora perfoliata und sclerotina etc.). — Zum 

 Schluss stellt Verf. nochmals „das zerissene Areal, das sporadische, 

 oft isolierte Vorkommen dieser interessanten Vertreter des Westens 

 in scharfen Gegensatz zu der continuierlichen, geschlossenen Ein- 

 wanderung pontischer Genossenschaften in der Nordostschweiz". — 



M. Brockmann— Jerosch (Zürich). 



Dewey, L. H., The Zapupe Fiber Plant of Eastern Mexico. 

 (Science. N. S. XXV. N^. 645, p. 743—744.1 10 May '07.) 



An abstract of a paper read before the Biological Society of 

 Washington March 9, 1907. Two species of Agave are cultivated 

 under the name Zapupe in the states of Tamaulipas and Vera 

 Cruz. Large plantations aggregating 4,000,000 plants have been set 

 out during the last four years. Two kinds of Zapupe are distin- 

 guished, „Zapupe verde" with light green leaves and a very sharp 

 terminal spine grooved at the base, and the „Zapupe azul" with 

 bluish glaucus leaves and terminal spines usually with an irregu- 

 larly diamond-shaped fiattened area on the face but without groove 

 or Channel. The Zapupe verde has long been grown for fiber by 

 the Indians ofTautoyuca, Vera Cruz, and may be Agave angus- 

 tifolia Haw. which has been referred doubtfully to A. rigida. The 

 Zapupe azul agrees exactly in habit, form of leaf and spines with 

 „Tequila azul", Agave tequilana Web. which is cultivated extensi- 

 vely near Tequila, Jalisco, for making the liquor called „Tequila". 



The fibers of both species are very similar in character and are 

 finer and more flexible than either Yucatan or Bahama sisal. 



Both species of Zapupe have rigid straight leaves 1 to 2 m. 

 long with small marginal up-curved spines. Henequin {A. rigida, 

 elongata (Jacobi) Baker and sisal {A. rigida, sisalana Engelm.) both 

 have broader, thicker and less numerous leaves than the Zapupes. 



W. T. Swingle. 



'■^' 



Gagep, C. S., Remarks on the Formation of Aerial Tubers 

 in Solanum Tuberosum (Science. N. S. XXIV. W. 624. p. 770—771. 

 14 Dec. 1906.) 



An abstract of a paper read at the Torrey Botanical Club on 

 Oct. 31, 1906. A potato shoot b'^'aring a tuber developed in daylight 

 was exhibited. This aerial development of tubers, so often recorded, 

 is held to render very improbable the theory of Noel Bernard 



