SMITH AND KINYOUN's DESCRIPTION 27! 



The parasite is actively motile, having both a vermicular, (con- 

 tractile) and spiral movement. It moves forward in a very peculiar 

 manner, the long whiplike process is thrust forward by a spirillar 

 motion, followed by a contracture of the body. 



We have not so far been able to determine its intimate structure, 

 further than the limiting membrane, and the protoplasmic substance of 

 the body. 



Two sizes of the parasite have been seen in all the specimens exam- 

 ined, the larger appears to be more numerous, and contains considerably 

 more granular material than the smaller, and usually two or more 

 vacuoles. Whether these two sizes represent male and female, has not 

 been determined. We are inclined to believe from our observations, 

 that these do represent the male and female, because we have observed 

 in more than half the fresh specimens, the joining of a large and small 

 parasite in such a way as to appear to be something more than accidental. 



The pathological changes caused by this parasite is a rapid distruc- 

 tion of the red blood cells, causing an acute anaemia. The changes 

 occur in the blood coincident to the invasion of the parasite. In one 

 horse which had been ill seven days, the red blood cells numbered 

 3,500,900, the white, 14,500. In another, ill six weeks, the red blood 

 cells were 3,200,000, and the white were 13,900. The blood of a healthy 

 horse, taken as a comparison, gave red blood cells, 6,900,000, white, 

 9,800. There is also a slight diminution in the amount of htemaglobin, 

 about 85 per cent. 



After convalescence has been fully established, no parasite can be 

 found, the blood gradually assumes its normal constitution. 



The parasite is not confined to the blood, as it can be demonstrated 

 in the serous effusions. 



It is quite easy to detect, all that is necessary is to make a micro- 

 scopical examination of fresh blood films, a i in. objective will suffice. 

 Dried films, fixed and stained with any of the nuclear dj'es. 



The organism appears to be a strict parasite. It lives but a short 

 time after removal from the body, the longest time which it has been 

 kept alive in blood serum, was not more than ten hours. 



The parasite has many of the properties in common with the filaria, 

 and resembles more nearh' that of filaria perstans, only it is smaller, 

 and its movements dissimilar. Yet on the other hand, the clinical his- 

 tory of animals infested by it, the changes occurring in the blood, the 

 lesions observed in post mortem, point very strongly towards its classifi- 

 cation with the spirochaete. 



The mode of transmission has not yet been studied. It does not 

 appear to be highly contagious, as it does not appear to spread from one 

 to another, even under the most favorable circumstances. 



It more nearly resembles malaria in this respect. It is more than 

 probable that its extra corporeal state is different, or another supposition 



