Recent studies of the olive-tubercle organism / by Erwin F. Smith.

  • Erwin Frink Smith
Date:
1908
Catalogue details

Licence: In copyright

Credit: Recent studies of the olive-tubercle organism / by Erwin F. Smith. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    20/24 (page 40)
    On glycerin agar a dry, white, rough, scaly growth was obtained. Growth on this inediuni was very abundant in the thermostat at 31° C. (50 times as much as at 20° C.) In agar stabs the surface growth was thin, white, finely granular under the lens, finally spreading. A distinct stab growth appeared and this was best at the top. The surface colonies on gelatin develop rapidly and are circular. J The margin is fimbriate, as in the case of Bacillus suhtilis, i. e., fringed with many parallel filaments. Next to this fringed portion in colonies two days old is a finely granular portion consisting of actively motile short rods. The center of the colony contains also ^ tangled chains. These colonies measured 5 to 10 mm. in diameter a and the gelatin wius fluid e.xcejit at the margin of the colony. 1 Gelatin stab: Growth gray white, best at the top; licpiefaction S rather rapid. It begins in about twenty-four hours at 24° C. and I usually ends in five or six days. The tube of li(|uefaction is at first H crateriform, becoming saccate. W A jiellicle forms on the surface of milk. In litmus milk there was ft some formation of alkali but no distinct development of acid. Theft milk must therefore be coagulated by a lab ferment. In my hands■ the .solution of the prwipitated curd wjus not as rapid as describedB by SchifF. I In Pctri-dish jioured jilates at 2.5° and3()°C. the growth of the sur-H face colonies on + 15 agar is rapid. They are round, .soon becomingB irregular, rhizoid; the lobes are often brancheil re])eatedly, as in theca.se ■ of Bacillus arouleac, if the agar is not too dry. The surface is smooth■ or slightly roughened, gray white, edges entire, becoming variouslyH lobate. Long, narrow crystals are sometimes fouml in agar cultures. H On jiotato with 5 jier cent glycerin added, growth at first wasB white or gray white, becoming isabella colored, growth abundant,® spreailing, rhizoid, dull (shining under hand len.s) rugose with den.se^ angleworm-like folds. Growth on common potato is similar, that is, a much wrinkled,® rather ilrv looking, spreading surface layer develops quickly. This* soon thickens and the numerous worm-like fohls disappear, so that® at the end of si.x or .seven days the surface pre.sents a smooth, thick,® shiiung layer. The substratum meanwhile acquires a slight pinkish ■ tinge or red specks appear here and there. The starch in the potato is destroyed ami growth continues for some weeks. The medium ■ remains neutral or with slight variations to either side of the litmus I neutral jioint. The potato cylinders are softened; after six weeks only traces of starch remain. i ' In Uschinsky’s solution the growth was copious but the rim wasj • scanty. Xo growth was obtained in peptone water with 0.2 per centf