VETERINARY SCIENCE AND PRACTICE. 187 



'tibU' cattle without rauf^ing ili^ease, ami that iioniiiftTtiouis i-attlc tirk.-, after liaviiig 

 lived for tieveral i^ueees.'^ive generational on h;u.sceptil)le eattle without cauHing disease, 

 may produce fatal case?* of Texas fever after having lived for a single generation on 

 an animal from infestetl territory. The virulence of the infection is in no wuy 

 influenced hy the length of time which has elapsed since the southern animals were 

 removed from the Texas fever area. 



J note on the vildlitii of the Koutlurn ixittlf tick (pp. 41, 42). — Ticks were collected from 

 a cow of the expei'iment station of the Bureau and placed in cotton-stoppered Hasks. 

 Eggs were soon laid, and on ^larch 11 they had nearly all hatched. The young 

 ticks remained without food, except the empty egg shells and dead bodies of the 

 adults, and without water until July 21, when they were plai-ed on a cow. The 

 majority of them were still alive and developed into full-sized adults l)y August 13. 

 They produced fertilized eggs which subsequently hatched. The possibility is sug- 

 gested of cattle ticks outliving an infection of Texas fever and becoming annually 

 reinfected in the spring. 



A note 0)1 the persistence of the IVxasfeeer organism in. the hloodof c((ttle (pp.42, 4.'>). — 

 On October 4, 1895, 2 calves about 5 months old received liypodermic injections oi 

 l)lood from a southern cow. The calves suffered a very mild attack of Texas fever. In 

 .\ugust of the following year the blood of these calves was used for inoculating 2 

 northern cows. Acute cases of Texas fever developed, and one of the animals died. 

 The experiment shows that infectious blood when injected into young cattle in the 

 fall of the year, although producing a very mild attack in them, may render the 

 blood of the young cattle sutiiciently virulent to cause fatal cases of Texas fever in 

 adult cattle 10 months later. 



.1?* experiment la blood and serum injections in connection irith Texas ferer inrestigalions 

 (pp. 43-52). — Experiments in inoculation with blood and serum from recovered cat- 

 tle indicated that large doses of blood or serum may produce a milder form of the 

 disease than small doses. In experiments along this line on 8 cattle; the amount of 

 blood used for inoculation ranged from 10 cc. to 400 cc, and inoculations were made 

 subcutaneously or intravenously. The injections were given on August 1. The first 

 attack of Texas fever began about August 10. The cattle recovered and suffered a 

 second attack about the middle of September. At this time one of the animals died. 

 The results obtained from these experiments showed that the quantity of blood from 

 an inmume cow used for inoculation has no influence upon the severity of the inocu- 

 lation disease, and that no difference is noted in the effects of intravenous and sul)- 

 cutaneous injections. A do.se of 10 cc. of blood is recommended as most satisfactory 

 •for inoculation purposes. The experiments indicated that the antitoxin which is 

 present in the blood of immune cattle can not be introduced into susceptible cattle 

 in quantities which will serve as a protective agent. 



Hemorrliagic septicsemia in cattle, S. D. Brimhall and L. B. Wu.son {Jour. 

 Coniji. Med. and Yd. Arrh., .n (1900), Xo. 1^, pp. 7i^~^-7^i).— Three outbreaks of this 

 disease occurred in ^Minnesota during the fall of 1900. In 3 herds, containing 67 ani- 

 mals, 37 were affected and all died. The chief symptoms were loss of appetite, fever, 

 lameness, swelling of the legs and submaxillary region, and black or l)loody dis- 

 charges. Death usually occurred in from 6 to 24 hours. The lesions found on post- 

 mortem examination were chiefly hemorrhagic areas in the subcutaneous connective 

 ti.ssue, nmscles, lymph glands, and external organs. The cervical lymph glands, 

 heart, spleen, and intestines were most affected. Post-mortem examination was made 

 on 9 animals, and a l)acillus was ol)tained from all cases apparently identical with 

 that of hemorrhagic septicjcniia described by other authors. Inoculations of ral)bits, 

 guinea pigs, and calves produced the characteristic symptoms of the disease. Exper- 

 iments in innnunizing animals by inoculation with Altered cultures yielded fairly 

 satisfactory results, although the number of experiments was too small to determine 

 the degree of immunity thus produced. 



2453— No. 2—01 7 



