Wachstum der Bakterien auf Agar mit 20 % Humanserum. Zunächst Bildung von Myelinfiguren, dann von Sphaero- und Tafelkristallen und schließlich - nach Beendigung des Wachstums - von Nadelkristallen.

Corynebacterium mirabile was isolated from the genitary tract of human males. They are rod shaped bacteria which are facultatively anaerobic. On protein-free media only rods are formed associated with a minimum amount of formed products. Film E 1117 shows the growth of bacteria on agar to which 20% human serum has been added. In association with rapid multiplication of the bacteria myelin figures are produced; later on spherical and tabular crystals are formed additionally and finally, after multiplication has stopped, needle crystals are formed.