1. Selective breeding of sugar-beets in russia and the U.S.S.R.

   • Alexander Archimowitsch

   OriginalPaper Pages: 1 - 37

2. Prospects of application of biological control in forest pathology

   • Mihailo Krstic

   OriginalPaper Pages: 38 - 44

3. The medullosan pteridosperms

   • Wilson N. Stewart
   • Theodore Delevoryas

   OriginalPaper Pages: 45 - 80