March, 1922. 



SCIEXTIFIC AGRICULTURE 



223? 



tions. Tlie work done in II was qualitalive. 

 One hundred and thirty-three cultures 

 which dissolved milk to a greater or lesser 

 extent have been recovered. On page 217 

 a description of the type of dissolving 

 is given and the grouping of the cul- 

 tures according to the mode of dissolving 

 milk is presented. On page 217 Table I 

 the sources from wliich the milk-dissolving 

 organisms have been isolated are tabulated. 

 The propriety of grouping our cultures ac- 

 cording to their reactions to milk may be 

 questioned from the systematic standpoint. 

 The procedure however, is in harmony 

 with the prime object of tlie investigation 

 — the securing of data with respect to the 

 spoilage of milk. It is noted on page 217 

 that a break in the continuity of the work 

 left us with only seventy-eight of the one 

 hundred and thirty-three cultures avail- 

 able for further examination. On pages 

 217 to 218 certain features of t;ie seventy- 

 eight cultures are recorded, and on page 

 219, Table II, the sources, grouping, and 

 cultural features of the seventy-eight milk- 

 dissolving organisms are presented in tab- 

 ular form. It will be observed from our 

 "observations on cultural studies," page 

 218, that in this investigation, the most 

 common type of organism responsible for 

 the dissolving or peptonizing of milk is a 

 Gram positive staphylococcus which fer- 

 ments glucose and lactose to acid, and li- 

 quefies gelatin. More than fifty per cent 

 of the staphylococci are from, milk pro- 

 cured vinder aseptic conditions, and the 

 series includes strains from the milk of 

 each of eleven cows. See qualification on 

 page 218. 



III. Six of the sevent3'-eight strains have 

 ])een examined in greater detail. Cultures 

 63, 75, 86 and 122 — isolated from middle 

 milk of CoAv 98, middle milk of Cow 121, 

 strippings of Cow 51, and strippings of 

 Cow 86, respectively — are each classified 

 as of the type Staphylococcus aureus (Ro- 

 senbach) (29), Culture 126, isolated from 

 middle milk of Cow 135 is classified as 

 Bacillus alholactis (Migula) (36). Culture 

 127, isolated from foremilk of Cow^ 56. is 

 placed intermediate between the genera 

 ProtcKS and Zopfins (29) (37) (38). 

 CONCLUSIONS. 



At the present juncture of the investiga- 

 tion, and with the limited amount of data 

 at our disposal, we do not feel justified in 

 drawing definite conclusions. 



There is, however, sufficient evidence to 

 warrant tlie suggestion that in certain 

 cases the time occupied by milk in clotting 

 is much shorter than can be considered to 

 be legitimate. As yet no correlation of 

 the "time occupied in clotting" with the 

 "actual period of usability" of milk is 

 presented. Nevertheless the phenomenon 

 of clotting may be regarded as a guide to 

 the comparative period of usability of (a) 

 various individual milks (b) milks pro- 

 duced at various specific centres. The ex- 

 tending of the period occupied by clotting 

 and hence the extending of the period of 

 usability of milk is an accomplishment 

 w-ithin the reach of all those engaged in 

 the production and management of milk 

 for sale. 



Further, it would seem that tlie results 

 Ave have recorded permit of the tentative 

 suggestion that the organisms recovered 

 from the milk procured direct from the 

 udder — even Avhen adequate precautions 

 are taken against external contamination — 

 are not Avithout significance Avith respect 

 to responsibility for the spoiling of milk, 

 particularly the spoilage Avhich is the re- 

 sult of or accentuated by the dissolving or 

 peptonizing fermentations of milk. 



References. 



1. — Moore & Ward 1899. — Source of Gas 

 and Taint producing Bacteria in 

 Cheese Curd. Bull. 158 Cornell Uni- 

 versitv Agr. Exp. Sta., Ithaca, N,Y. 



2,— Harrison 1902-3.— The Bacterial Con- 

 tamination of Milk and Its Control. 

 Report Ont. DairA'men's Assoc, and 

 Trans. Can. Inst. Vol. VII, Pg. 495. 



3._Savage, W. G. 1908.— Bacterial Stu- 

 dies of Milk from HealthA' & Diseased 

 Cows. Report Med. Officer 1906-7 

 Local Govt. Bd. App. B. No. 4, Pgs, 

 3-50, London. 



4.— Harrison & SaA^age 1912.— The Bacte- 

 rial Content of the Normal Udder. 

 Trans. Roy. Scty. Can. 3rd Ser. VoL 

 V, Section IV, Pgs. 31-40, Ottawa. 



5.— Bergev, D. H. 1904.— Source and Nat- 

 ure of Bacteria in Milk. Bull. No. .125 

 Dept. of Agric. Pa. 



6.— Conn, Esten & Stocking, 1906.— Clas- 

 sification of Dairy Bacteria. Report 

 Storrs (Conn.) Agr. Exp. Sta. Pgs. 

 92-203. 



7.— Harding & Wilson, 1913.— A Study 

 of the udder Flora of Coav Tech. 



