SPIRILLA RESEMBLING CHOLERA. 341

In alkaline peptone solution a slow but luxuriant
growth takes place.

Spirillum Milleri.—This spirillum (Fig. 96) was found
in the mouth by Miller in 1885. It: resembles the cholera

^. f, ^~ ; ,

FIG. 96.—Spirillum Milleri, from an agar-agar culture; x 1000 (Itzerott and

Niemann).

spirillum somewhat, but is much more like the spirillum
of Pinkler and Prior, with which many bacteriologists
think it identical.

Upon gelatin the colonies are small, finely granular,
have a narrow border-zone and a pale-brown color. The
gelatin is rapidly liquefied.

Upon agar-agar a thick yellowish layer is produced.

The organism seems not to be pathogenic.

Spirillum Aquatilis.—Giinther in 1892 found this or-
ganism (Fig. 97) in the water of the river Spree. It is
similar to the cholera spirillum in shape, has a long
terminal flagellum, and is motile.

The colonies which form upon gelatin are circular,
have smooth borders, and look very much as if bored out
with a tool. They have a brown color and are finely
granular. In gelatin puncture-cultures the growth occurs
almost exclusively at the surface.

The agar-agar cultures are similar to those of cholera.

Scarcely any development occurs in bouillon. By the