Bacterial Disease of the Squash-hug. 349 



pathogenic organisms, by means of which a toxic excre- 

 tion of bacteria may be secured in a way convenient for 

 chemical study. The mixture which I have tried is form- 

 ulated as follows: 



Water 1,000 



Glycerine 40-50 



Sodium Chloride 5-7 



Ammonium Lactate 10 



Calcium Chloride 0.1 



Magnesium Sulphate 0.2 



Potassium Bi phosphate l 



To the above formula Uschinsky added a little sugar 

 for some organisms, and urea or uric acid for others. 

 With the bacillus of this squash-bug disease an addition 

 of 5% sugar gave an abundant growth, but the develop- 

 ment was very slow. Three weeks after the inoculation 

 a thick yellowish white film had formed on the upper 

 surface, and the bottom of the flask was likewise thickly 

 covered with a sedimentary deposit. During the first 

 two weeks' of growth the liquid had a slight pinkish 

 coloration. An addition of 10% sugar gave much less 

 growth than the above, but the pink coloration was more 

 marked. Urea to the amount of one half per cent, with 

 the formula mentioned, also urea one half per cent, and 

 sugar 5% in each of two other flasks, differed very little 

 from the culture first described, although the pink color 

 was more lasting, and possibly the growth of less extent. 

 The value of these media for securing the toxic principle 

 for analytical purposes cannot yet be determined, as the 

 chemical work has not been completed. 



A culture consisting of fermentation broth in bent 

 tubes gave no gas production. The ingredients of the 

 broth used were as follows: 



Water 1.000 c.e. 



Glucose 20 grms. 



Peptone 10 grms. 



Sodium Chloride 6 grms. 



In a nitrate solution the organism grows well., but 

 there is no reduction of the nitrates, as shown by nega- 

 tive results (absence of red color) from the usual test — 



