INFECTIOUS ABORTION IN SWINE 417 



small dew drop like colonies, which on being examined with the 

 microscope resembled in every respect colonies of the B. abortus 

 of Bang. Examined by the aid of the hand lens they were nearly 

 water clear to direct light and of bluish tint to reflected light. 

 They were round and raised, with exceptionally well defined 

 borders. Most of these minute dew drop colonies were homo- 

 geneous, with the exception that a few of them had a few granules 

 in the center, typical of many colonies produced by the B. abortus. 

 Viewing the larger colonies under the microscope, it was seen 

 that the centers had assumed a granular consistency, while the 

 outer portion was homogeneous and transparent. The colonies 

 on some of the plates were so large that they might have been 

 taken for some other species, measuring If mm. in diameter. 

 These conformed, however, to similar colonies of B. abortus 

 derived from the tissues of the cow. To reflected light they had 

 assumed an amber color, the centers having a whitish appearance. 

 On examining stained preparations of these colonies, the mor- 

 phology of the organism was identical, so far as we could deter- 

 mine, with B. abortus. On examining the plates carefully with 

 a Coddington lens and microscope, colonies resembling those 

 mentioned and measuring from a pinpoint to 1.5 mm. in diameter 

 were seen on streaks made from the blood of the umbihcus, on 

 the streaks made from the small nodule-like growths on one of 

 the afterbirths, and from the afterbirth and internal organs 

 of the fetuses. Eighty-four colonies in all were counted on 

 streaks made from one of the small nodules. Some of these colonies 

 were so small that they could not have been seen with the naked 

 eye. There were one or two colonies on the streaks made from 

 the livers. The plates streaked with the amniotic fluid were 

 almost completely covered with contaminating bacteria, but, 

 in the clear spaces five dew drop colonies were noted. The streaks 

 of the contents of the stomachs of both pigs showed numerous 

 small dew drop colonies. Streaks from the kidneys were negative. 

 Stained preparations had been made from the different organs 

 mentioned but were not examined until the cultures had de- 

 veloped. Upon examining these preparations, germs identical 

 with the Bacillus abortus (Bang) were seen in large numbers in 

 those made from the stomach contents of the pigs. 



