348 VETERINAUY NOTES 



Present condition ;- -Tlie pony Ims no iiiai-kcd signs of illness aiifl is well-nourished. 

 The blood coagulates rather more quickly than usual and is a little greasy, but not specially 

 so. There are no skin lesions of any kind. As stated, filarial embryos were present 

 in it. The blood in which they were found was derived from one of the branch veins of the 

 ear and about one micro-filaria was present in each blood film — fresh or stained — examined, 

 I'.e. in about every small drop of blood. 

 I haractiTs of The parasite :''-In the fresh blood the parasite is found to be exceedingly active, rapidly 



Kp.ir. Mt traversing and leaving the field of the microscope, twisting, coiling and lashing about 

 incessantly, so much so that in a thickish film it causes a certain amount of destruction 

 of the red cells. It possesses a blunt cephalic and very sharp caudal end. No evidence of 

 a sheath can be seen. In cover-glass preparations it remains alive for at least six hours, 

 though its movements become more sluggish and it rarely coils itself up as it does at first. 



In ordinary preparations stained by the Leishnuui niethoil and carefully measured by 

 means of tlie ocular micrometer, it is found to vary in length from llo/i to 180^i. In 

 citrated blood and in de-htemoglobinised films this measurement becomes considerably less, 

 i.e. 80fi to 95/i or thereby. Doubtless the medium or the process of staining causes some 

 alteration. The average width is 4;u, but this also varies a little in stained films. These 

 measurements were confirmed later by Bruce's method for trypanosomes. 



The cylindrical body, especially in smears fixed in alcohol, is seen to be coarsely 

 granular, and it jiresents, as a rule, four or five clear areas or spots. There is one at the 

 head end, possibly of the nature of a cephalic prepuce as it varies in size and is not always 

 visible. It is rounded, exhibits no hook or spicule, stains a faint blue, measures about I'O/i 

 in length and is continued into the central column of the cells as a narrow but very distinct 

 slit about 3^1 long by '5^ broad. This does not show in all specimens and would seem to 

 depend on what aspect of the parasite happens to be presented to view. In a parasite 

 measuring 115^ in length the following spots were made out, apart from the clear area at 

 the cephalic end and the accompanying slit : — 



1. A well-marked somewhat oval bay, with centre 345^ from the anterior extremity 

 and measuring 45/1 x 15^. 



2. A small indefinite central spot with centre 73-5/i from the anterior extremity of 

 the worm. 



3. A large clear area with centre 90/i from the anterior extremity and measuring 

 6^1 X 3^ but occupied in part by cell nuclei. This is the most characteristic and constant 

 of the spots and the cell nuclei always seem to encroach upon it. 



4. A small but distinct triangular caudal end, including the tip of the tail, which 

 does not take on the stain and which is not seen in all specimens. 



In other examples one has observed a small lateral bay between No. 3, and the 

 tail tip and also a larger lateral bay, two-thirds of the way between the anterior extremity 

 and No. 1 (Plate XVII., fig. 2). 



The spots are not so evident in parasites observed in de-hsemoglobinised films or 

 in smears of citrated blood. Examination with high powers reveals nothing of further 

 note beyond well-marked annulations of the cuticle which are indicated in the drawing. 



I unfortunately neglected to apply the special staining methods of Fiilleborn and 

 Rodenwald. 



The only other filaria so far met with in horses in the Sudan, is a small nematode which 

 I found in the crust of a skin ulcer sent me by Captain Williams, late of the Sudan 

 Veterinary Department. He believed the condition to be Bursati. 



A filaria has been discovered by Major Ensor in donkey's blood in the Bahr-El-Ghazal 



