A. B. WiCKWARE 
10 
of the investigations. Subsequently, identical parasites were demon¬ 
strated in the blood of ducks similarly affected on the Experimental 
Farm, Ottawa. In view of the fact that no record of this parasite can 
be found, we are naming it Leucocytozoon anatisr 
The parasites were present in large numbers in the peripheral 
circulation of ducks in which the affection ran an acute and fatal course. 
Smears from the spleen also showed an abundance of parasites. These 
protozoa gradually diminished in number in the ducks which made an 
apparent recovery, while in contact birds which presented no clinical 
manifestations, parasites were not demonstrable. Examination of the 
blood of other contact fowls as well as ducks from sources where the 
disease was not prevalent, failed to reveal any hematozoa. 
Morphology. The shape of the parasites is fairly uniform, although 
there appears to be considerable pleomorphism in the gamete forms. 
The predominant type is a spindle-shaped organism, 35p. to 60p, in 
length by lOp, in width, showing an oval, elongated or irregularly shaped 
nucleus, with a dark chromatic band extending along one border. 
The nucleus stains, with Giemsa, a dark blue having a granular appear¬ 
ance. In the centre may be observed a small chromatin staining body 
varying shghtly in shape. The cytoplasm appears almost transparent 
or at most stains a faint pink and terminates at each end in an acute 
angle. Although, as previously mentioned, there is marked uniformity 
in shape, it might be advisable to state that considerable variation 
occurs in the staining characteristics of the mature forms. The 
chromatic band is similar in all instances, but in certain adult forms the 
nucleus stains indistinctly a light blue with radiating filaments of 
chromatin throughout. 
Examined in fresh blood preparations, the parasite appears to be non- 
motile, but as it has recently been shown at Khartoum that motility 
is present in some of the larger forms, further studies must be under¬ 
taken before making a positive statement in this respect. 
Pathological Anatomy. Microscopically the visceral organs fail to 
show any abnormahty excepting an acute haemorrhagic inflammation 
of the large intestine immediately behind the caeca. The normal body 
fluids appear imaltered, while scrapings from the intestinal wall and 
examinations of the bowel content show an absence of coccidia or other 
parasites. In some of the ducks examined, the mouth and pharynx 
contained a considerable quantity of blood and mucus, the former 
probably being due to traumatic injuries sustained through the head 
coming in violent contact with the ground during the paroxysms. 
2—2 
