srmorn.'KTOSis of Sudanese fowls 
45 
between slide and cover glass. They are more easily recognised in preparations stained by 
the Giemsa or Leishinan methods, the former being on the whole the more satisfactory. 
I employ the made-up fluid Giemsa, supplied by Griibler in a strength of 7 drops of the stain 
to 4'5 c.c. of distilled water. The film is fixed for ten minutes in absolute alcohol, then 
placed film side down in a special staining dish or in a shallow Petri capsule with its ends 
supported by tiny glass rods (broken pieces of vaccine capillary tubes serve the purpose) and 
the stain is poured in. Staining is continued for a quarter of an hour or longer, the film is 
washed, 
minutes 
dried, and examined under a i' 
is usually insufficient, and, as 
-in. oil immersion, 
will be seen, led 
Staining for five or even ten 
to mistakes being made and 
caused erroneous impressions. 
Plate V., fig. 1, shows the 
different aspects presented by 
the stained parasite. 
In Fig. 6fl shows a form in 
which three chromatic dots are 
clearly visible. They occur in 
the course of the nuclear helix, 
for as in other spirochaetes the 
nucleus is diffuse,and examina¬ 
tion with the highest powers 
of the microscope shows that 
there is a central nuclear core 
surrounded by a periplast. 
I think it is this periplast 
which gives the appearance 
of an undulating membrane 
described by Prowazek for 
Sp. gallinarum, while a frayed, 
fragmented periplast doubtless 
furnished the peritrichous 
flagella demonstrated by 
ISorrel. In a, as in all the 
other forms, the pointed ends 
of the parasite are well seen ; 
b shows an appearance which 
suggests longitudinal division. 
1 have never seen transverse 
division occur in this 
spirochaete; c is one of the 
short thick forms, which some 
have supposed to be a female gamete. Another not quite so broad is also shown. Both d 
and e represent types of the parasite in which there are breaks or gaps in the central 
core, the nature of which is considered later; tj is one of the long combined forms 
in which it would seem two spirochaetes are united by their extremities; while h shows a 
fairly long thin form, claimed by some to be a male gamete, in which the spiral turns are 
small and numerous; and k is a form of similar length, but with only a few large spirals; 
/ shows clumps of the parasites in the condition of pullulation preceding the crisis. The 
remaining drawings shovv common forms, either outstretched or curved and looped. 
As regards size, there are short forms containing 4 spirals and measuring 9,« in 
6.—Forma of Fowl Spiroch®te ia the peripbera blood 
Staining 
methods 
Various forms 
of parasite 
