1. Families with mental defectiveness heredity and natality. Means of prevention

   • G. P. Frets

   OriginalPaper Pages: 297 - 330

2. Inheritance of colours in phaseolus vulgaris L.I.

   • R. Prakken

   OriginalPaper Pages: 331 - 408

3. The cytology of certain diploid, triploid and tetraploidAvena hybrids

   • W. Ellison

   OriginalPaper Pages: 409 - 418

4. A comparison of the segregations of wildVersus normal or cultivated base in the grain of diploid, tetraploid and hexaploid species of oats

   • E. T. Jones

   OriginalPaper Pages: 419 - 434

5. Genetical observations with the tea-plant

   • S. J. Wellensiek

   OriginalPaper Pages: 435 - 452