530 A MANUAL OF BACTERIOLOGY 



Kraus and Prantschoff x noticed that certain vibrios 

 produced hsemolysin and dissolved red blood-corpuscles, 

 but came to the conclusion that no recently isolated 

 true cholera vibrio is hsemolytic. 



The question of the formation of hsemolysins by the 

 cholera and allied vibrios is important. 



Strong. 2 in the Philippines, found that all vibrios which 

 agglutinated well with a cholera serum were genuine 

 cholera vibrios and that none of them was hsemolytic. On 

 the other hand, Baerthlein 3 found that seven freshly 

 isolated strains of the cholera vibrio were definitely hsemo- 

 lytic in suspensions of sheep's corpuscles in from twenty- 

 four to forty-eight hours. Van Loghem 4 employs goat's 

 blood-agar plates in hsemolytic tests for the cholera vibrio. 

 He asserts that goat's blood is quickly hsemolysed by 

 hremolysing cholera-like vibrios, but that recently isolated 

 cholera strains, if they hsemolyse at all, do not do so for 

 some time twenty-four to forty-eight hours. 



Van Loghem 5 distinguishes two types of blood solution, 

 viz. hsemolysis proper and hsemo-digestion. He asserts 

 that the apparent hsemolysis on a blood-agar plate 

 occasionally occurring with the true cholera vibrio is 

 really hsemo-digestion. He distinguishes the two condi- 

 tions by the tint of the hsemolytic zone red in true 

 haemolysis and greenish in hsemo-digestion and spectro- 

 scopically the affected zone shows oxyhsemoglobin in 

 hsemolysis but not in hsemo-digestion. The blood agar 

 used for the plates is composed of ordinary nutrient agar 

 with an addition of 11-12 per cent, of defibrinated goat's 

 blood. 



Greig, using 1 c.c. of a 5 per cent, suspension of goat's 



W ien. klin. Woch., 1906, p. 299. 

 Philippine Journ. of Science, vol. v, 1910, p. 403. 

 Arb. aus dem kaiserl. Gesundheitsamte, xxxvi, 1911. 

 Centr.f. Balct., Abt. i (Originate), Ivii, 1911, p. 289. 

 Ibid., Ixx, 1913, p. 70. 



