354 THE DISEASES AND DISORDERS OF THE OX. 



occurred. When a bacterial growth did occur, it did not appear 

 until the third, fourth, or fifth day, in gelatine tubes kept in the 

 incubator at a temperature of 20*^ C, and there was only one, 

 or there might be two, or at the most three, minute colonies. 

 In fact, the blood of patients affected with scarlatina contains 

 only a few organisms. If we make a series of cover-glass 

 preparations after the Weigert-Koch method — using about as 

 much blood as would be contained in a culture-tube — and stain 

 with gentian-violet, methylen-blue, or other dyes, and examine 

 witli a high-power oil-immersion lens, it is only rarely that we 

 see in one or other such specimen a stained granule or a dumb- 

 bell of such a size that it may be looked upon as being presum- 

 ably a micrococcus or a diplococcus of the species that we find 

 by cultivation does exist in the blood of patients affected with 

 scarlatina. The scarcity of these micrococci is a peculiar feature 

 of scarlatina as opposed to anthrax, septicaemia, &c., in which 

 the particular germs are found in considerably quantity. 



A micrococcus similar to that obtained from the Hendon cows 

 was obtained from the blood of four human beings suffering 

 from scarlatina, and also after death from the blood taken from 

 the heart of a fifth patient who had died in consequence of the 

 affection. In the case of the living persons from whose blood 

 the micrococcus was obtained, the temperature was at its maximum 

 at or about the day on which the culture experiments were made. 

 In three of the four experiments on living scarlatina patients 

 from whose blood an organism identical with that found in the 

 Hendon cows was recovered, there developed in the culture- 

 tubes, besides the colonies of the special micrococcus, colonies 

 of other micrococci also ; and Dr. Klein states that if he had 

 not been familiar beforehand with the appearances of the par- 

 ticular organism obtained from the Hendon cows, he would have 

 had great difficulty in identifying it in these specimens of blood. 

 Moreover, the other micrococci of these three scarlatina cases 

 were much more easily discoverable than was the one which was 

 common to all five of the cases of scarlatina, and which were 

 known as occurring in the Hendon cow disease. In order to 

 prove the connection between a disease and a particular organism, 

 it is necessary to reproduce the same disease by inoculation of 

 suitable animals with specimens of that particular organism 

 proved to be free from admixture with any other organism. 



