Twelve tube cultures representing different chemical and morphological groups.
| Bacillus Megaterium | Rhodospirillum rubrum |
| Branhamella catarrhalis | Serratia marcescens |
| Clostridium sporogenes | Spirillum volutans |
| Lactobacillus acidophilus | Sporosarcina ureae |
| Micrococcus luteus | Streptomyces griseus |
| Pseudomonas fluorescens | Vibrio fischeri |