SCIENCE AND INDUSTRY. 
* There are many references to abortion in cattle in old books on farriery and. 
the diseases of animals, and throughout the nineteenth century veterinary autho- 
rities considered the question of its contagious and non-contagious nature. 
Gradually opinion hardened in favour of the contagion theory. “ Rolof, quoted 
by Zundel, in 1871 believed that abortion was due to the entrance of an infective 
agent by way of the vagina, and stated that a discharge from the genitals always 
preceded the act of abortion, St. Cyr, in 1875, believed abortion to be due to 
an undetermined but specific agent. Lehnert, in 1878, produced abortion in 
cows by putting the discharges and fatal membranes from aborting cows into 
the vagina. In 1885 Nocard undertook the investigation of abortion in cows, 
and in the valuable report published in 1886 he brought forward excellent cir- 
cumstantial evidence of the contagious nature of the disease. Nocard also sub-— 
mitted the disease to a bacteriological study.”* 
“In a report to the Highland and Agricultural Society of Scotland in 1889, 
Woodhead, Aitkin, McFadyean, and Campbell showed that abortion could be 
produced in cows and ewes by inserting into the vagina plugs of wool con- 
taminated by the discharge of aborting cows. A cow was also made to abort. 
a living foetus, by subcutaneously injecting her with the discharge of an aborting 
cow.””* 
The great advance came, however, in 1897, when Professor ‘Bang, of the — 
Copenhagen Veterinary School, published results of his researches into the 
disease. Bang was able to examine the uterus of a cow which had been 
slaughtered while showing premonitory symptoms of abortion. He found 
“between the uterine mucous membrane and the foetal envelopes an abundant 
odourless exudate.” 
It was in microscopical preparations from this exudate that Bang discovered 
the very small bacillus, apparently in pure culture, which he suggested was the 
specific cause of the disease, Bang concluded that contagious abortion was a 
specific uterine catarrh, due to infection with the bacillus—a non-motile, non- 
Gramstaining organism, shorter than the tubercle bacillus. Bang further suc-_ 
ceeded in growing the organism in pure culture. The medium he used was a 
mixture of the ordinary nutrient agar and nutrient gelatine with half its volume 
of raw blood serum. A number of test-tubes are supplied with 10¢.c. each of 
the mixed nutrient gelatine and agar and sterilized in the ordinary way. To 
start a culture a tube of the medium is liquefied in a water bath and then 
has added to it the warm sterile serum, which is mixed by rapidly rotating the 
tube. The infective material from a freshly opened uterus is added and inti-— 
mately mixed, and the tube is rapidly cooled in the vertical position, It is 
then placed in the incubator at 37.5C. On the third or fourth day, the growth 
of the contagious abortion-bacillus begins to make its appearance in a plane 
about one-fifth of an inch below the surface of the medium. There is no apparent 
growth in the depth of the medium, but in time the thin disc below the surface 
may gradually thicken in an upward direction, and even come to the surface. 
‘In the earliest stages one can usually make out with a hand lens the separate 
colonies, minute, transparent, and roundish, with finely dentate edges on high 
magnification. 
Because of this peculiarity of growth, Bang inferred that he “ had thus not 
to do with an exrobie bacterium, which would have pushed its growth as far 
as the surface of the nutritive media, and still less had he to do with an 
* Report of Departmental Committee on Epizo tic Abort 
eat NEL D. t pizootic ortion in Cattle, 
36 
