78 EXPERIMENT STATION EECOKD. 



the detection of native bodj' substances foreign to the blood; biological diag- 

 nosis of pregnancy; the optical method and its use in pathology; the signifi- 

 cance of milk for the suckling; the use of the optical method in the field of 

 infectious diseases; etc. A large bibliography is appended. 



Investigations in regard to streptolysin, O. von Hellens {Centbl. Bakt. 

 [etc.], 1. AM., Orig., 68 (1913), No. 7, pp. 602-6U, fi9-s. 12).— The results of this 

 extensive investigation show that streptolysin formation takes place very rapidly 

 and can be noted 1 hour after inoculation, A maximum formation can take 

 place within 7 to S hours. The greatest amount of hemolysin formation, which 

 depends upon the nutrient medium and the strain of bsicteria employed, is said 

 to be between the seventh and eighteenth hour. As soon as it reaches its fas- 

 tigium it begins to decrease, and in the first 24 hours this decrease is very rapid. 

 In the greatest number of cases no hemolysin was noted after 8 to 13 days. 

 In anaerobic cultures streptolysin formation and depreciation take place in 

 almost the same manner as in aerobic cultures. In the latter cases, however, 

 they were produced a little more slowly, and a lower amount was formed. 



The best nutrient medium for the streptococcus was a horse serum-bouillon 

 containing from 40 to 50 per cent of a serum inactivated at 56° C. for one-half 

 hour. Rabbit serum (10 per cent) bouillon was inferior to ascitic fluid (33 per 

 cent) bouillon. Only a slight development of streptolysin took place in a plain 

 alkaline peptone bouillon, but when 5 per cent of peptone was added to cultures 

 in other media there was a marked increase, in one case over 300 per cent. 

 Evidently a prolysin (Walbum) is present in such cultures which is destroyed 

 whep, the bacteria are continuously cultivated in the thermostat. The hemo- 

 lysin present in seruui'- and ascitic fluid-bouillon cultures is filterable. The fil- 

 trate from horse serum bouillon cultures is from 1.1 to 1.4 times weaker than 

 the cultures themselves. 



In human, horse, bovine, sheep, goat, dog, pig, rabbit, guinea pig, and pigeon 

 blood appreciable quantities of antistreptolysin could not be noted. The hemo- 

 lytic action of streptolysin showed a different intensity at different temperatures, 

 being from 4 to 6 times more active at 37° C. than at room temperature, while at 

 nearly freezing temperature it is practically inactive. The greatest resistance 

 toward hemolysin was noted with the blood of the goat and sheep, that of man, 

 horses, bovines, and pigeons coming next, and this being followed by rabbit, dog, 

 pig, and guinea pig blood. A decoloration of the blood of the horse, bovine, 

 sheep, and goat took place as a result of hemolysis. The blood corpuscles of 

 man, the pig, and the guinea pig were agglutinated in some cases. ■ 



The hemolytic principle of streptolysin was soluble in ether, and almost the 

 entire quantity present in the culture could be extracted with this solvent. The 

 streptolysin present in the filtrate was labile and was inactivated rapidly by 

 cooling to —16°, at +4 to 5°, at room temperature, or by heating at 37° or 

 above. Horse serum bouillon streptolysin was the most resistant. The strep- 

 tolysin extracted from the filtrates was thermostable. The addition of hydro- 

 chloric acid seemed to increase the inactivation of streptolysin by heat. The 

 rate of preventing inactivation by sodium hydroxid. seemed to bear some relation 

 to the hydrogen ion concentration of the solution. 



The laws and rules and regulations governing live stock sanitary control 

 ■work in Tennessee, 1913-14 (Xashville: Tenn. Dept. Agr., 1913, pp. Jfi, fig. 1). — 

 A compilation of the various laws, rules, and regulations relating to live stock 

 sanitary control work in Tennessee. 



The results of meat inspection in Brunswick, 1905-1911, C. Sander (Beitr. 

 Statis. Braunschifcig, 1913, No. 26, pp. 23-47). — A statistical report of inspection 

 work. 



