September 27, 1912] 



SCIENCE 



411 



to 200. On the other hand, of 127 cows 

 which had either aborted or came from in- 

 fected herds, 62 (nearly 50 per cent.) gave 

 some agglutination, although only 38 agglu- 

 tinated in the dilution of 1 to 100 or more. 

 Wall pointed out from his results that the use 

 of the agglutination method alone is likely to 

 lead to some errors and to many cases of 

 uncertainty. In the main, however, as the 

 above two papers indicate, its results are satis- 

 factory. 



Three papers dealing with the diagnosis of 

 the disease in this country have recently ap- 

 peared. The first of these is by Larson,' in 

 which he concludes that the complement fixa- 

 tion test offers a reliable and satisfactory 

 method of diagnosis. Another paper which is 

 a continuation of the work started by Larson 

 is by Hadley and Beach," in which again the 

 complement fixation reaction is used alone. 

 A third paper is by the writer" in which both 

 the agglutination and complement fixation 

 reactions were tested. 



The results of these papers are in agreement 

 with European investigations and indicate 

 that a reliable method of diagnosis in this dis- 

 ease is now available. 



The perfection of these methods of diagnosis 

 undoubtedly marks the greatest step towards 

 the eradication of this disease which has yet 

 been made. By their use it is possible to 

 separate the infected from the uninfected ani- 

 mals. By proper methods of isolation and 

 disinfection much can then be done towards 

 ridding a herd of the disease. This is espe- 

 cially true in herds where the infection has 

 just started. 



'Larson, W. P., "The Complement Fixation 

 Reaction in the Diagnosis of Contagious Abortion 

 of Cattle," Jmr. Infect. Dis., Vol. 10, pp. 178- 

 185, March, 1912. 



» Hadley, P. B., and Beach, B. A., ' ' The Diag- 

 nosis of Contagious Abortion in Cattle by Means 

 of the Complement Fixation Test, ' ' Wisconsin 

 Agric. Exper. Station, Eesearch Bulletin No. 24, 

 June, 1912. 



" Surface, Frank M., ' ' The Diagnosis of Infec- 

 tious Abortion in Cattle, ' ' Ann. Rpt. Kentucky 

 Agric. Exper. Station, 1912 (Bulletin 166), pp. 

 303-366, June, 1912. 



In spite of the fact that the cause of this 

 disease was discovered by Bang as early as 

 1896, very little progress has been made to- 

 wards the perfection of a cure or a preventa- 

 tive. The most important contribution to 

 this side of the subject also comes from Jen- 

 sen's Laboratory and is by Dr. Halfdan 

 Holth." In an excellent contribution Holth 

 gives many valuable observations on the 

 growth and biology of the abortion bacilli. 

 Many experiments dealing with the theory of 

 immunity are also reported. The matter of 

 most immediate interest, however, is that deal- 

 ing with the artificial production of immunity. 

 Holth clearly demonstrates that it is entirely 

 possible to produce agglutinins and anti- 

 bodies in animals treated with either living 

 or dead cultures and with serum. Injection 

 of living culture produces the largest amount 

 of immune bodies and these remain in the 

 blood for a longer period of time than with 

 other treatments. Injection of a killed cul- 

 ture is the next most efficient way while the 

 effects of an immune serum appear to be 

 slight and transitory. 



Experiments with rats and mice show that 

 injection of either a serum or a properly pre- 

 pared vaccine will protect them against an 

 otherwise deadly dose of the abortion bacilli. 



Whether these results will be borne out by 

 experiments on cows or not is still unsettled. 

 Experiments are under way in Denmark and 

 other places which will settle this matter be- 

 fore long. 



In this connection should be mentioned the 

 excellent review by Oluf Bang" of the work 



" Holth, Halfdan, ' ' Kastningsbacillens Biologi 

 og Immunitetsf orholdene ved Sygdommen, ' ' 

 Maanedsshrift for Byrlaeger, XXII., 1911. Also 

 " Untersuehungen fiber die Biologie des Abortus- 

 bacillus und die Immunitiitsverhaltnisse des infek- 

 tiosen Abortus der Einder, " Zeit. f. InfeMions- 

 hrankheiten usw. der Haustiere, Bd. X., 1911, 

 94 pp. 



^- Bang, Oluf, ' ' Schutzimpf ung gegen den inf ek- 

 tiiisen Abortus," Klimmer u. Wolff-Eisner's 

 ' ' Handbuch der Serumtherapie und Serumdiag- 

 nostik in der Veterinarmedzin, " Leipzig, 1911, 

 pp. 202-223. 



