188 EXPERIMENT STATION RECORD. 



after 4 days' preservation, with negative results in both cases. No 

 bacterial growth had taken place in the blood, but the organism of 

 Texas fever was destro3^ed. A cross Hereford and Shorthorn bull, 2 

 years of age, was imported from Missouri and inoculated in the ordi- 

 nary way, but died on the third day after inoculation. It was supposed 

 that in this case death resulted from scptica?niia. 



The general results of these experiments may be summarized as 

 follows: Blood from recenth^ immunized animals gave a milder and 

 less protracted form of inoculation fever than a similar aniovuit of 

 blood from a native animal. If animals were allowed a sufficient time 

 to recover completely from the inoculation fever, they did not suffer 

 when exposed to tick infestation. The experiments indicate that it is 

 possible to take engorged ticks from recently inmiunized animals and 

 ship them to considerable distances, thus using them as receptacles for 

 containing the virulent blood. It appears also that although the inocu- 

 lation fever which results from the use of such blood is mild, the immu- 

 nity produced is complete. 



Studies on cattle plague, M. Nencki et al. {Arc/t. Sci. Biol. [St. 

 Fetersbunj], 7 {1S09), Xo. 4, 2>2)- 303-336).— The authors' researches 

 upon cattle plague were begun in the province of Kouban in 1895. It 

 was soon discovered that the blood of animals which had recovered 

 from this disease contained a substance which confers immunity on 

 other animals. Considerable progress has been made in perfecting 

 means for the preparation of the antitoxin and in taking blood from 

 experimental animals. The animals which are to be immunized receive 

 a dose of 0.2 cc. of virulent blood. After about 2 days, when it 

 appears that the disease has invaded the organism, the animal receives 

 a dose of therapeutic serum. Immunization has been accomplished 

 In' the authors hy 2 methods, which they have called rapid and slow, 

 respectiyel3^ 



The benefits derived from immunization are stated by the authors as 

 follows: The danger of contagion from the excrement of the animals is 

 avoided and abortion in pregnant cows prevented. The injection of 

 immunizing serum has no influence upon the secretion of milk. Ani- 

 mals which are susceptible to cattle plague may be immunized in 3 

 ways, b}^ the serum alone, b}' the serum and ^'irulent blood, and by 

 inoculating the animal with virulent l)l()()d and then giving an injection 

 of serum after the disease has shoAvn its first symptoms, which occurs 

 usualW in from 1 to 8 days. 



In experiments which were conducted to determine the value of bile 

 in the production of immunity, the authors came to the following con- 

 clusions: The green bile of animals killed by severing the jugular vein 

 from 5 to 7 days after the beginning of the fever is most effective in 

 producing immunity. The liile of animals which have died of cattle 

 plague is yellowish in color and is not suitable for use in preventive 



