Protozoan Cattle Fever. Texas Fever. Paludism of Cattle. 547 



site intra-globular and free, and in the latter an active whirling 

 motion was kept up by means of the flagellum at its pointed end. 

 As usually arranged in pairs (gemina), whether inside or outside 

 the globule, they are connected by the flagellum attached to their 

 pointed ends. Careful observation enables one to detect in the 

 pyriform mass a small brightly refrangent point like a nucleus. 

 In this form the piroplasma is 3 to 4/a in length. 



After 4 or 5 hours, and on toward the 8th, the piroplasma has 

 assumed the round or oval form with a small linear prolongation 

 (flagellum) and shrunken to i to i J^/u, in diameter. All the 

 piriform bodies pass into the rounded so that this last is the 

 second stage of their development and not the first as was 

 formerly supposed. The round forms are always present in great 

 numbers in the cortex of the kidney in the second stage of the 

 disease (toward the subsidence of the hsemoglobinuria). The 

 refrangent nucleus is no longer to be seen. 



After, one, two or more days there appears in the round para- 

 site a chromatine mass, which breaks up into 2, 3, 4 or 5 smaller 

 chromatic bodies, which I,ignieres considers as germs. He has 

 seen no division of the protoplasm, but on the contrary the germs 

 escape, yet remain for a time attached to the outer surface of the 

 parent organism. They .show rapid jerking movements. 



Lignieres claims to have followed all these changes in the blood 

 kept in a sterilized glass cup at room temperature or in the ther- 

 mostat, and in the stomach of the tick, as well as on the warm 

 stage of the microscope. 



He claims to have made a further success in cultivating the 

 para.site in ox-blood .serum highly charged with haemoglobin. It 

 was only occasionally, and by the use of blood extraordinarily rich 

 in the parasites, that succe.ss was obtained. In one such case he 

 produced five successive cultures, the product being the rounded 

 forms only and within the.se the germs. There were no piriform 

 bodies. The.se are not formed outside of the red globules. The 

 third successive culture in this medium grew with great readi- 

 ness, producing larger parasites with less di.spositiou to contract, 

 but the fourth and fifth cultures were encreasingly poor. Inocu- 

 lation with these cultures failed to produce the disease. To ex- 

 plain this the doctrine of passive germs, strong for survival, but 

 weak pathogenically, is hazarded. 



