The Elements of Bacteriological Technique Part 72

2. Colonies Confluent: Surface elevation and character of edge, as for plate cultivations (_vide_ page 263).

Chromogenicity: As for plate cultures.

~Gelatine Stab Cultures.~--

(A) _Surface Growth._--As for individual colonies in plate cultures (_vide_ page 261).

[Ill.u.s.tration: FIG. 150.--Stab cultivations--types of growth: a, Filiform; b, beaded; c, echinate; d, villous; e, arborescent.]

(B) _Line of Puncture._--

Filiform: Uniform growth, without special characters (Fig. 150, a).

Nodose: Consisting of closely aggregated colonies.

Beaded: Consisting of loosely placed or disjointed colonies (Fig. 150, b).

Papillate: Beset with papillate extensions.

Echinate: Beset with acicular extensions (Fig. 150, c).

Villous: Beset with short, undivided, hair-like extensions (Fig. 150, d).

Plumose: A delicate feathery growth.

[Ill.u.s.tration: FIG. 151.--Stab cultivations--types of growth: f, Crateriform; g, saccate; h, infundibuliform; j, napiform; k, fusiform; l, stratiform.]

Arborescent: Branched or tree-like, beset with branched hair-like extensions (Fig. 150, e).

(C) _Area of Liquefaction_ (if present).--

Crateriform: A saucer-shaped liquefaction of the gelatine (Fig. 151, f).

Saccate: Shape of an elongated sack, tubular cylindrical (Fig. 151, g).

Infundibuliform: Shape of a funnel, conical (Fig. 151, h).

Napiform: Shape of a turnip (Fig. 151, j).

Fusiform: Outline of a parsnip, narrow at either end, broadest below the surface (Fig. 151, k).

Stratiform: Liquefaction extending to the walls of the tube and downward horizontally (Fig. 151, l).

(D) _Character of the Liquefied Gelatine._--

1. Pellicle on surface.

2. Uniformly turbid.

3. Granular.

4. Mainly clear, but containing flocculi.

5. Deposit at apex of liquefied portion.

(E) _Production of Gas Bubbles._

~Shake Cultures.~--

1. Presence or absence of liquefaction.

2. Production of gas bubbles.

3. Bulk of growth at the surface--aerobic.

4. Bulk of growth in depths--anaerobic.

~Fluid Media.~

~1. Surface of the Liquid.~--

Presence or absence of froth due to gas bubbles.

Presence or absence of pellicle formation.

Character of pellicle.

~2. Body of the Liquid.~--

Uniformly turbid.

Flocculi in suspension.

Granules in suspension.

Clear, with precipitate at bottom of tube.

Colouration of fluid, presence or absence of.

~3. Precipitate.~--