Organography of plants, especially of the archegoniatae and spermaphyta . theirmorphological significance. It is quite possible that the pneumatophores havearisen in quite the same way as, only probably earlier than, the structures which wefind in Carapa moluccensis doing the work of pneumatophores. In this species See Part I, p. 260. * Goebel, Pflanzenbiologische Schildemngen, ii (1893). Prior to this these inlercellular spaceswere regarded as reservoirs of air which hardly explained their occurrence in the epigeons parts ofmarsh-plants. ?? Westermaier, Zur Kenntniss der Pneumatophoren ; Bota
Organography of plants, especially of the archegoniatae and spermaphyta . theirmorphological significance. It is quite possible that the pneumatophores havearisen in quite the same way as, only probably earlier than, the structures which wefind in Carapa moluccensis doing the work of pneumatophores. In this species See Part I, p. 260. * Goebel, Pflanzenbiologische Schildemngen, ii (1893). Prior to this these inlercellular spaceswere regarded as reservoirs of air which hardly explained their occurrence in the epigeons parts ofmarsh-plants. ?? Westermaier, Zur Kenntniss der Pneumatophoren ; Botanische Untersuchungen im Anschlussan eine Tropenreise, Heft i; Freiburg, Schweiz, 1900. * Besides, there is no far-reaching anatomical difference between root and shoot. The usualscheme of shoot-structure is, for instance, in abeyance in many species of Utricularia and Stylidium. PNEUMA TOPHORES 279 horn-like or finger-like outgrowths arise ^ by inequalities in the secondary growth inthickness in the upper part of the roots which creep near the surface of the In my view it is most probable that these pneumatophores are roots. In Bruguieraknee-like curved portions of the root rising above the mud perform the same ^ See Karsten, Uber die Mangrove-\egetation im Malayischen Archipel, in Bibliotheca Botanica,xxii (1891), p. 51. 28o THE ROOT IN PTERIDOPHYTA AND SPERMOPHYTA function. In Lumnitzera numerous lateral roots ascend in a negatively geotropicmanner from the horizontal roots and then bend downwards with a sharp the point of bending special large lenticels are developed, often a centimeterin diameter, and these perform the work of gas-exchange. Taxodium. I can do no more than mention here the root-knees of Taxo-dium which discharge a similar function. The biological significance of the air-roots first of all suggested upon the groundof their anatomical relationships, and the localities in which they were found ^, wasexperimentally supported by Karsten and Gr
Size: 1291px × 1935px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookido, booksubjectplantanatomy
