222 



SCIENTIFIC AGRICULTURE 



March, 1922. 



nature of the medium employed. From 

 the condensation Avater of agar, young cul- 

 tures are actively motile. Stained by Van 

 Ermengem's method, the flagella proved 

 to be peritrichic. 



The liquefaction of gelatin is stratiform 

 with no putrid odor and is complete in one 

 month. In mill' at SJi/o deg. C. the reac- 

 tion is possibly more correctly described as 

 digesting tlian dissolving; within 48 hours 

 digesting commences, and in 14 days a ge- 

 latinous pencil clot is noted, and a definite- 

 ly putrid odor ; later, a brilliant red fluid, 

 having a pronounced "beef extract" odor 

 is recorded, and this condition persists for 

 at least two months. Litmus mill- at 371/2 

 deg. C. is digested; in 21 days, a marked 

 turnip odor is apparent, and in one month 

 the "beef extract'' odor already noted, is 

 definitie. In milk + peptone at 37%° C. 

 no colour is developed, the "beef extract" 

 odor is less marked, and otherwise the re- 

 actions are common to those recorded for 

 milk. In milk at room temperature, the 

 reactions are slower than those detailed 

 for milk at a temperature of 371/2 deg. C, 

 but in two months the medium is almost 

 completely digested, and an odor of "beef 

 extract ' ' is definite. The organism is kill- 

 ed on exposure to a temperature of 58 deg. 

 C. for 10 minutes. Dextrose, saccharose, 

 levulose, mannite, raffinose, and glycerin, 

 are fermented to acid within 24 hours. The 

 reaction to raffinose is slight. To lactose 

 and galactose the reaction is first faintly 

 acid, later alkaline. Maltose and inulin are 

 not fermented. 



This organism closely resembles B. 

 cochleatus Conn, Esten and Stocking, (6) 

 varying in that the colonies on gelatin are 

 simple not lobed, the liquefaction of the 

 gelatin stab is stratiform, the gro'v\i;h on 

 agar is white and spreading. The char- 

 acteristics of Culture 127 closely resemble 

 those determined for our Culture 126, 

 W'ith the unsurmountable excei)tion that 

 Culture 127 does not form spores. The 

 failure to produce endospores excludes this 

 strain from the Bacillaceae (29). Auto- 

 matically it is included among the Ba-cte- 

 riaceae (29) and the cultural reactions 

 seem to infer a place between the Tribe 

 Zopfeae (29) and the Tribe Bactereae 

 (29). Hence our strain becomes a varia- 

 tion of the Genus Zopfius on the one hand 

 and of the Geaus Proteus on the other 



hand. The variations of the strain from 

 either are distinct and definite, Wenner & 

 Kettger. (37), Enlows, (38). We .suggest 

 the placing of Culture 127 as a strain in- 

 termediate between the genera Proteus 

 (29) (37) (38) and Zopfius (29) (37) 

 (38). 



General Summary. 



An investigation into the spoilage of 

 milk and the possible "period of usabil- 

 ity" of milk was commenced in the Pro- 

 vince of British Columbia some two years 

 ago, and the work is still in progress. The 

 classic laboratory methods for the deter- 

 mination of the bacterial content of milk 

 have been used, but our principal activity 

 has been the conducting of "clotting" 

 experiments by the adoption of the "Fer- 

 mentation Test". Our paper reports work 

 on three phases of the investigation : — I. 

 milk clotting tests: II. a more or less de- 

 tailed treatment of the "dissolving" or 

 "peptonizing" fermentation, and III the 

 cultural characteristics leading to t\^ clas- 

 sification of certain of the organisms isolat- 

 ed during the research. 



1. Milk clotting tests have been carried 

 on at four centres. The records of two 

 hundred and forty-five samples are sub- 

 mitted. Incubated at 371/2 deg. C. the 

 shortest period occupied in clotting was 9 

 hours, and the longest period 48 hours. The 

 data ])resented is concerned solely with 

 samples of mixed milk. The number of 

 samples reported upon is not sufficiently 

 large to warrant more than tentative con- 

 clusions. For the present it is to be in- 

 ferred that such procedures in methods of 

 production and management shall be in- 

 stituted as will insure at least that all milk 

 shall attain to our tentatively recorded 

 "maximum period of usability." The re- 

 lationship of "time occupied in clotting" 

 to "actual period of usability" is referred 

 to on page 215. 



II. The frequency with wliich at each 

 centre tlie "dissolving" or "peptonizing" 

 of the clot took place led to further en- 

 quiry into this phenomenon, and one of 

 the four centres was selected for the more 

 detailed studies. Samples of milk drawn 

 direct from the udder into sterile test tu- 

 bes — observing tlie necessary precautioHS 

 — samples of mixed milk, of water, of 

 feeds and bediling were taken ; and agar 

 plates were exposed under varying condi- 



