1. Quantitative evolution XV. Numerical evolution

   • James Small

   OriginalPaper 01 May 1949 Pages: 1 - 40

2. Biotypology IV. Morphological typology of the individual and of groups

   • Walter Brandt

   OriginalPaper 01 May 1949 Pages: 41 - 56

3. A speculation concerning some principles of biology

   • E. S. Roberts

   OriginalPaper 01 May 1949 Pages: 57 - 74

4. The units of experimental taxonomy

   • D. H. Valentine

   OriginalPaper 01 May 1949 Pages: 75 - 88

5. L'écologie

   • Hermann Gisin

   OriginalPaper 01 May 1949 Pages: 89 - 100