Medical Officers of the Army of India.
2
9
Form η.
1
. Growth in neutralised agar-agar media. —Occurring rapidly and freely both
superficially and interstitially ; surface-growth usually tenacious or ropey; elements
distinguished by their persistently small size, and usually occurring either as minute,
almost straight rods, or of short oval cocci and plano-convex bodies.
2. Growth in non -neutralised agar-agar media. —Purely superficial and relatively
rapid.
3. Growth in common gelatine media. —The process of liquefaction retarded ;
channel of liquefaction originally presenting a cylindrical form, but now invariably
closely similar to that formed in cultivations of ζ ( P l a t e I , F i g . 4
a . P l a t e I I
b , F i g s . 1 - 8 ,
η ) .
4. Growth on potatoes. —Vigorous growth has never been obtained in spite of very
numerous attempted cultivations ; the abortive growths which occasionally occur always
distinguished by their very pale, more or less whitish colour.
5. Growth in bouillon. —In cultivations in neutralised media now presenting no
characteristic peculiarities ; when first obtained, distinguished by incapacity for giving rise
to cholera-purple on the addition of acids.
Form θ.
1.
Growth in neutralised agar-agar media. —Rapid both superficially and intersti-
tially; surface-growth very frequently more or less adhesive ; elements of very small size,
consisting of well-curved, short commas.
2. Growth in non-neutralised agar-agar media. —Extremely retarded and purely
superficial ; consisting of small coccoid elements occasionally associated with a small
number of short straight rods.* (Plate IV, Fig. 5.)
3. Growth in common nutritive gelatine. —Liquefaction originally occurring very rapid-
ly, but, after prolonged cultivation in agar-agar media,slowly and attended by very abundant
deposit, the deeper and narrow part of the channel ordinarily conspicuously irregular and
knotty owing to localised centres of specially active growth. (Plate 1, Fig.2, b, Plate III
a, Figs. θ.)
4. Growth on potatoes. —Extremely rare save in entirely abortive form ; when vigorous
forming thin, very moist, ochreous-pink expansions composed of small commas, like those
occurring in the growths on neutralised agar-agar media.
5. Growth in bouillon. —Presenting no distinctive features on neutralised media,
occurring slowly in non-neutralised media in the form of a thin, imperfect, superficial
pellicle composed of coccoid elements like those developed in connection with non-neutra-
lised agar-agar media. (Plate IV, Fig. 5.)
Form ι.
1. Growth in neutralised agar-agar media. —Superficial and interstitial growth
rapid ; the surface growth forming a thick stratum of absolutely incoherent consistence and
warm ochreous tint and very frequently conspicuously tuberculate ; interstitial growth
not accompanied by the conspicuous darkening of the medium accompanying that of every
other form save λ , but sometimes by a peculiar olive colouring ; elements distinctly comma-
tous, but differing greatly in different cultivations both in regard to size and degree of
curvature.
* When cultivated in relatively highly alkaline media it is distinguished from all the other forms by a
capacity for interstitial growth which forms a dense column around the needle-track.