192
Contagious Pleuro-Pneumonia of Goats
of solid spherules from which radiate one or more delicate filaments, with
usually, but not necessarily, an attached terminal ' daughter ' spherule.
The same diagram includes a further phase which seems to combine
features of the variants of the stellate forms with the ' conidioid ' production
just described.
Figs. 10 to 13 of Plate XII depict peculiar complex forms common in
all preparations.
Figs. 1, 2 and 3 of Plate XIII are three enlargements of a typical field,
which depicts many of the forms described. The preparation is relatively
thick, and the results of Brownian movement are evident in places (15 minutes
exposure), but for some reason many of the bodies in this field were stationary,
and could thus be photographed. The explanation is probably that they
were adherent to the glass surface as the result of some electrical pheno-
menon.
Diagram 4, Plate XV represents a phase which has been observed in
two separate preparations. When first observed the body had the appearance
shown at (a). Ten minutes later the original filament had grown out and bi-
furcated, and two other long and two short filaments had developed (b). The
filaments were all in very active movement, and discernably growing. Ten
minutes later the original filament was observed to break away as shown in
the diagram (c), together with another growing filament. Two minutes later
all but two of the filaments had broken away. In a further five minutes there
was evidence of further growth of the longer of the two, with the develop-
ment of a small granule at its tip, and of the development of two further
filaments. The field then presented the appearance shown at (d).
Similar forms were numerous in both preparations, and are represented in
figs, e to h. In fig. g the filaments were too numerous to count, but exceeded
20. In fig. h the filament was found by measurement with the eyepiece
micrometer to be approximately 22 µ long (exact measurement was impossible
owing to the active movements of the filament.) The size of the parent rings
was approximately 4 µ. Numerous ' rings ' with no attached filaments were
present in both preparations. (Fig. i). In some, minute granules were evident
on the circumference (Figs. j and k) and are perhaps the sites of the origin of the
filaments. It is noteworthy that within one such ring a small coccoid body, in
very active Brownian movement, was observed, obviously trapped between
the two glass surfaces and the ring itself, against which it was in constant
impact. There can thus be no doubt that the structure of such forms is a true
ring. Two such have been recorded photographically in Plate XII figs. 3 and
14.
The phase represented in Diagram 5 of Plate XV has been observed in
only one preparation, and figs. a to d of the diagram show the variations in
form observed over a period of 65 minutes. The phase was reminiscent, of
that just described, but differed in three clear respects :—(a) the parent ring
was very irregular in outline, not the true circle of the other, (b) it visibly
increased in size, a phenomenon not observed with the other phase, (c) it was
of much more robust texture, sufficiently so for photography of the parent
' ring', but not of the filaments, which were in very active movement
throughout.
Six other separate specimens observed are dipicted in figs. e to j of
Diagram 5, Plate XV. The initial observations of this phase were made