382 EXPERIMENT STATION RECORD. [Vol. 37 



"The condition of the animal (amount of fat), the temperature of the atmos- 

 phere, and the percentage of humidity are factors which should be considered in 

 determining the normal temperature of the pig." 



The etiology of hog cholera. — Preliminary report, F. Pkoeschek and H. A. 

 Seil (Jour. Amer. Vet. Med. Assoc, 51 (1917), No. 1, pp. 64-69, pis. 2).— The 

 authors prepared smears from the blood of 6 pigs in the advancetl stages of 

 hog cholera and from the blood of 28 pigs artificially infected with virus. All 

 the animals were examined post-mortem and the characteristic lesions of the 

 disease established. 



The smears, after being fixed, were thoroughly washed and then stained in 

 a 1 per cent aqueous solution of methylene azure containing 1 per cent of 

 phenol and finally mounted in paraffin or cedar oils. The general blood pic- 

 tures are described in detail. 



In all the preparations a very small diplococcus uniformly less than 0.2 fi 

 in size was found. They were stained either a deep blue or a metachromatic 

 violet. The micro-organisms were al.so found in the urine of three pigs arti- 

 ficially infected with hog-cholera virus. 



The close resemblance of the changes in the blood picture in hog cholera to 

 those of typhus fever is pointed out and briefly discussed. 



The artificial cultivation of the organism observed in the smears and a 

 histological .study of the changes taking place in the blood vessels of animals 

 affected with cholera are in progress. 



On the pathology and treatment of pernicious and infectious anemia of 

 the horse, III, J. N. Riks (Tier, ^fcd. Vet.. 92 {1916), No. 1-2. pp. 14-20).— U 

 is concluded that the pernicious anemia of Lorraine and adjacent territory is 

 a gastrophilic anemia in the great majority of cases. 



Vaccination against infectious arthritis of foals due to Bacillus abortus 

 equi. J. B. Hakdenbergh (Mo. Bill. Utatc Live titock Sanit. li<l. [I'enn.l, J 

 (1916), No. 2, pp. 16, pis. S; Jour. Amer. Vet. Med. Assoc., 50 (1916), No. S, 

 pp. 331-349, figs. 6). — A number of cases in an outbreak of infectious arthritis 

 in foals are reported in detail. The organism causing the outbreak was found 

 to belong to a subgroup of the paratyphoid-entoritidis group wliich has been 

 isolated by various investigators. 



The complement-fixation and agglutination tests are dt^metl reliable for de- 

 termining the extent of the infection in the stable, but the best results are 

 obtained by repeating the tests at intervals of from three to four weeks. "Ani- 

 mals giving an agglutination reaction of 1:500 or over, with no complement- 

 fixation reaction, should be watched and reteste<l in three weeks. Immune 

 bodies in some ca.ses disappear rapidly." 



One ophthalmic test with a purified " abortin " is considered to be of no 

 value in determining infected animals. The possibility of using a different 

 preparation of abortin or a retest as yielding more satisfactory results is indi- 

 cated. Two or three injections of from 50,000,000 to 100.000.000 organisms, 

 followed by more if necessary, are considered to be nmch better than numerous 

 injections of small amounts. 



" The fact that all of the colts, either infected or later developing affections 

 of the joints, gave marked local rea<-tions to the bacteria may indicate such a 

 preparation to be of diagnostic value when injected or rather vaccinating foals 

 against joint evil, which do not at the time give serum reactions. Vaccination 

 of exposed foals with a specific bacterin appears to confer .some immunity to 

 the disease, and may also have some curative properties, as 7 out of 10 foals, 

 either thoroughly exposed to the inftx'tion or badly infected, failed to develop 



