1. The origin and function of self-incompatibility in flowering plants

   • R. G. Olmstead

   Review Pages: 127 - 136

2. Effects of high humidity and temperature stress on pollen membrane integrity and pollen vigour in Nicotiana tabacum

   • K. R. Shivanna
   • M. Cresti

   Original Articles Pages: 137 - 141

3. Critical studies on the sexuality of southern Argentinian Ericaceae

   • V. N. Cambi
   • P. M. Hermann

   Original Articles Pages: 142 - 149

4. Male sterility in birdsfoot trefoil (Lotus corniculatus L.)

   • V. Negri
   • B. Romano
   • F. Ferranti

   Original Articles Pages: 150 - 153

5. An electron microscope study on in vitro parthenogenesis in sunflower

   • Hua Yan
   • Hong-Yuan Yang
   • William A. Jensen

   Original Articles Pages: 154 - 166

6. Cellular energy levels and their effect on male cell abortion in cytoplasmically male sterile lines of Petunia hybrida

   • X. C. Liu
   • H. G. Dickinson

   Original Articles Pages: 167 - 172

7. A structural study on the mode of action of CHA^TM Chemical Hybridizing Agent in wheat

   • H. L. Mogensen
   • Juanita A. R. Ladyman

   Original Articles Pages: 173 - 183

8. Interspecific incompatibility due to stylar barriers in tuber-bearing and closely related non-tuber-bearing Solanums

   • Natalie K. Fritz
   • R. E. Hanneman Jr.

   Original Articles Pages: 184 - 192

9. The ultrastructure of polymorphic pollen grains of Canna indica L.

   • F. Chen
   • F. Ciampolini
   • M. Cresti

   Original Articles Pages: 193 - 198