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Full text of "Pathogenic Bacteria"

244                 PA THOGENIC BA CTERIA.

lander and a number of colonies consisting of fine, slender,
often somewhat nodose bacilli about the size and form of
the lepra bacillus.

These colonies were grayish-yellow, humped in the
middle, 1-2 mm. in diameter, irregularly rounded, and
irregular at the edges. They could be inverted entire
with the platinum wire and were excavated on the under
side. The consistence was crumbly.

When a transfer was made from one of these colonies
to fresh media, in a few days the growth became apparent
and assumed a band-like form, with a plateau-like eleva-
tion in the center.

The bacillus thus isolated grew with moderate rapidity
upon all the ordinary culture-media except potato. Upon
blood-serum the growth was more luxuriant and fluid
than upon the solid media. Upon coagulated serum the
growth was rather dry and elevated, and was frequently
so loosely attached to the surface of the medium as to
be readily lifted up by the platinum wire.

The growth was especially good upon sheep's blood-
serum with the addition of 5 per cent, of glycerin. The
growth upon the Ix)ffier-mixture was excellent.

Upon agar-agar the growth is not so good as upon
blood-serum ; it is more luxuriant upon glycerin agar-
agar than upon plain agar-agar; it is grayish and flatter
upon agar-agar than upon blood-serum. The growth
never extends to the water of condensation to form a
floating layer, as does that of the tubercle bacillus.

The colonies that form upon agar-agar are much like
those described by Bordoni-Uffredozzi, and appear as iso-
lated, grayish, rounded flakes, thicker in the center than
at the edges, and characterized by an irregular serrated
border from which a fine irregular network extends upon
the medium. These projections consist of bundles of the
bacilli.

Upon gelatin the bacillus develops well after it has
grown artificially for a number of generations. Upon
the surface of gelatin the growth is, in general, similar