Two culturing recipes were suggested for Pasteurella multocida and Pasteurella haemolytica, one partialy defined nutritive defined nutritive medium with 0.5 per cent yeast extract and one chemically defined medium. Both had been composed on the basis of studies into nutrient demand and into the effects of complex nutritive substrates. Both nutritive media are applicable also to culturing other bacterial species. (Among the strains tested so far were streptococci, staphylococci, Escherichia coli, pseudomonas, protest, Salmonella,, Shigella, and Haemophilus.)