From t h Biockmid taliorato*y, (lolmbridqe--Rcport to t h Medial ReaawcA Commit&. THE work that forms the basis of this report wae undertaken with a view to obtaining a transparent, steriliaable medium upon which the gonococcus would grow with such freedom that the preparation of vaccines would become a relatively simple matter. It ie well known that the ordinary nutrient media are not suitable for such purpoeee. It k true that Thalmann (1900 '9 waa able to obtain growth of the organism on

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... ary nutrient media brought to a special reaction. Picker (1906 u), Vannod (1907 and Wollstein (1 9 0 7 98) were eucceeaful in obtaining growth on Thalmann'e medium, but the two latter e h t e that the best results are always obtained on serum media. Other workers have found Thalmann's agar unarrtisfactory even for subcultures, and the uee of a nutrient agar enriched by the addition of aterile serum, Werthoim (1891 e4), blood, Abel(l893 l), or aecitic fluid has become general as the atandad method for the cultivation of the gonococcus in the laboratory. It is possible that the differenwe in opinion held by various workers on the suitability of relatively simple media may be partially dne to the biological variations in the atrain. Broughton Allcock (1 9 15 3, records one case in ten in which the organism grew readily on plain agar. We have isolated a Gram-negative diplococcus from the urethral diecharge which we imagined was the gonococcus until we found that it fermented cane-sugar and maltoae. It grows with fair freedom on ordinary nutrient agar. The adoption of media containing unheated eem, etc, was originally based on the idea that the gonococcue like other w a l l e d ' I delicate " organiems, required some special protein for its metabolism. This view hae been dieproved for the meningococcus by Jordan Lloyd (1 9 1 6 13) and by Flack (1 9 16 8) . The undoubted value of fresh blood, etc., as an addition to a nutrient meditim has been shown by these workem Recaived April 11, 1917. 268 SYDNEY FK COLE AND D. JORDAN LLOYD. to be due to certain speoial substances which may possibly prove to be the same aa the " growth hormona " deacribed by Hopkins (1 9 1 2 le) . These are generally known by the convenient but misleading name of " vitamines," introduced by Funk (1 9 1 2 g) , who was, however, mainly dealing with curative substances. The results of our researches lead us to believe that there are three important factors concerned in the growth of the gonococcus, namely-1. The concentration of hydrogen-ions, ie., the " reaction." 2. The concentration of amino-acids.