132 
KEPORT OF TRAVELLING PATHOLOGIST AND PROTOZOOLOGIST 
showocl that 70'4 per cent, of the leucocytes were eosinophiles. The presence or otherwise of 
ankylostomes W'as not determined. There was a considerable degree of ansemia. In the 
Bahr-El-Ghazal a case of hlackwater-fever was seen, but this revealed nothing further than 
the presence of malarial parasites of the malignant variety. Guinea worm was seen at several 
places, and is more fully discussed in the nest section. During the examination of the stools 
of cases in the Military Hospital, Khartoum, eggs of bilharzia were repeatedly encountered. 
Both the terminal and lateral spined eggs were found. 
Dracontiasis 
Dracontiasis 
Guinea Worm 
Plate IX., figs. 1-7 
Guinea-worm 
infection 
common at 
Wau 
Technique 
employed in 
studying 
embryos 
At Wau, in the Bahr-El-Ghazal Province, cases of guinea worm infection were common, 
and, owing to the kindness of Capt. M. G. Dill, then in charge of the Military Hospital, many 
cases of this disease were at my disposal, and I was able to conduct some experiments which 
confirm the results obtained by Dr. Leiper. Further, owing to a new method of fixation and 
staining, I was able to make out some new points in the anatomy of the guinea worm 
embryos. For the fixation of the embryos the following method was adopted. The active 
embryos from a guinea worm were placed in a test-tube containing about 1 c.c. of normal salt 
solution. The tube was then nearly filled with saturated solution of corrosive sublimate. 
This killed the embryos and fixed them in a few minutes. The contents of the tube 
were then centrifugalised for about a minute and the supernatant fluid removed. Distilled 
water was added, the tube gently shaken and again centrifugalised. By repeating this 
process four or five times nearly all the sublimate was removed. The tube was then 
filled with 70 per cent, alcohol to which a few drops of iodine solution were added. The 
tube was left standing upright, with the result that the embryos settled to the bottom. After 
five or six hours, the fluid was removed by means of a pipette and fresh 70 per cent, alcohol 
and iodine added. After this had acted for a simitar period it was removed and 70 per cent, 
alcohol alone added. To this was added one drop of Delafield’s haematoxylin and the tube 
put aside. By taking out a little of the sediment from time to time the progress of the 
staining could be watched. The staining of the embryos is slow, owing to the thick cuticle 
which covers them. It first commences in the region of the anus and of the gland-like organ 
which opens near the anterior end of the body. After about a week the whole embryo is 
stained, apparently by the stain gaining entrance by the natural apertures of the body. If the 
embryos appear not to stain, another drop of haematoxylin can be added. If too deeply 
stained, differentiation may be effected with 70 per cent, acid alcohol by removing the stain 
and filling up the tube with the acid alcohol, allowing the embryos to settle to the bottom 
and examining the sediment from time to time. When differentiation is complete 
remove the acid alcohol with a pipette and replace by ordinary 70 per cent, alcohol. 
If acid alcohol has been used, a drop of ammonia solution added to the 70 per cent, 
alcohol will “ blue ” the embryos. By adding glycerine to the contents of the tube, a drop at 
a time, the embryos may he thus transferred to a more convenient medium. Between each 
drop the tube must he gently shaken and allowed to stand about a quarter of an hour before 
the addition of another drop. The glycerine must not be made too strong nor added too 
rapidly, or shrinking of the embryos will result. Glycerine added to about 25 per cent, will 
he quite sufficient. In this medium the embryos may be readily examined with high powers 
by sealing the edges of the cover slips with paraffin or other fixative. This method has the 
