1. On the occurrence of nuclei in mature sieve elements

   • Ray F. Event
   • Jerry D. Davis
   • Frank J. Alfieri

   OriginalPaper Pages: 281 - 296

2. Polar transport and accumulation of indole-3-acetic acid during root regeneration by Pinus lambertiana embryos

   • Michael S. Greenwood
   • Mary Helen M. GoldSmith

   OriginalPaper Pages: 297 - 313

3. The fine structure of the cells that perceive gravity in the root tip of maize

   • B. E. Juniper
   • Anna French

   OriginalPaper Pages: 314 - 329

4. Influence of factors affecting germination on respiration of Phacelia tanacetifolia seeds

   • Shepley S. C. Chen

   OriginalPaper Pages: 330 - 335

5. Action of light and gibberellic acid on the growth of excised embryos from Phacelia tanacetifolia seeds

   • Shepley S. C. Chen

   OriginalPaper Pages: 336 - 340

6. Electron probe analysis of freeze-substituted, epoxy resin embedded tissue for ion transport studies in plants

   • André Läuchli
   • Arthur R. Spurr
   • Raymond W. Wittkopp

   OriginalPaper Pages: 341 - 350

7. The proportion of sieve elements in the phloem of some tropical trees

   • J. R. S. Lawton
   • M. J. Canny

   Short Communication Pages: 351 - 354

8. Embryogenesis and production of albino plants from cell cultures of Bromus inermis

   • O. L. Gamborg
   • F. Constabel
   • R. A. Miller

   Short Communication Pages: 355 - 358

9. Isolierung von Auxinen aus dem Chromatin regenerierender Erbsenkeimlinge

   • G. Fellenberg

   Kurze Mitteilung Pages: 359 - 361