VETERINARY SCIENCE. 243 



Live stock and poultry at the Loxiisiana State Station (Louisiana Stas. Bui. 

 SS, 2d -SI'):, pp. 075, 076). — Brief notes ou the station herd, a iKJCord of eggs laid ])y 9 

 breeds of chickens, each represented by 1 to 3 laying hens, and results of weighing 

 chickens of the same breeds. The chickens ^yete 3 nion.ths old. Light Brahma 

 gave the heaviest cockei'els, followed by Laced Wyandotte; Langshau the heaviest 

 pullets, followed by Light Brahma. 



VETERINARY SCIENCE. 



Additional investigations concerning infectious swine diseases, 



T. Smith and V. A, Moore {U. S. JJcpf. Ar/r., Bureau of Animal 

 Industrij Bui. (J, x^P- 117). — The subjects treated are the followiug: The 

 hog-cholera group of bacteria; experimeuts on tlie production of 

 immunity in rabbits and guinea pigs with reference to hog-cholera and 

 swine-plague bacteria; the variability of infectious diseases as illustrated 

 by hog cholera and swine i)lague; the eflect on the virulence of the 

 bacillus of hog cholera oi passing the microorganism through a series 

 of rabbits; the disposal of hog cholera and swine-plague bacteria 

 injected in small numbers into the subcutaneous tissue of pigs; and the 

 practical bearings of the above investigations. 

 The authors' summary on the subject of immunity is as follows: 



"(1) It is possible to produce immunity toward hog-cholera and swine-plaguc bac- 

 teria in the very susceptible rabbit and the less susceptible guinea pig. In the 

 rabbit the only promising method of immunization toward hog cholera is the use of 

 gradually augmented doses of attenuated cultures. 



'•(2) Immunization toward swine-plague bacteria is produced artiticially with 

 much greater ease than toward hog-cholera bacteria. 



"(3) The blood serum of animals protected against hog cholera and swine plague 

 is almost as efficacious in producing immunity soon after treatment as the bacteria 

 products obtained from cultures. 



"(4) Dirt'erent degrees of immunity in both hog cholera and swine plague lead to 

 different forms of the inoculation disease. The greater the immunity short of com- 

 jdete protection the more prolonged and chronic the disease, induced subsequentlj" 

 by inoculation. 



"(5) Pathogenic bacteria may remain in the organs of inoculated animals some 

 time after apparently full recovery. Their i^resence may or may not be associated 

 with lesions recognizable bj' the naked eye. 



"(6) The toxicity of sterilized cultures appears to be directly proportional to the 

 number of bacteria in the injected fluid. 



"(7) The results of Selander and Metchnikotf in the immunization of small animals 

 were obtained with swine-plague and not with hog-cholera bacilli." 



The following conclusions were reached relative to'the disposal of hog- 

 cholera and swine-plague bacteria injected into the subcutaneous tissue 

 of pigs: 



"(1) Both hog-cholera and swine-plague bacteria will remain alive in the sub- 

 cutaneous tissue for several days after their injection. 



"(2) The hog-cholera bacteria are taken up from the point of injection and dis- 

 tributed, to a certain extent, through the body. They are harbored for a limited 

 period of time in certain lymphatic glands, where they may be detected. They are 

 not found m the other organs of the body." 



