38 THE MICROSCOPE. Mar. 



with rounded ends. Their growth is most rapid at blood 

 heat ; thermal death-point, 140° F. They are long lived 

 and will endure most any kind of weather, and find their 

 way into the system through the medium of drinking 

 water, milk or other food. 



The pathogenic micro-organism of scarlet fever has not 

 as yet, been fully demonstrated, but some good German 

 and French authorities found in all these cases examined, 

 a streptococcus identical with the streptococcus of ery- 

 sipelas. Sternberg says: "In the diptheritic exudate 

 frequently seen in the angina of scarlet fever a strepto- 

 coccus is commonly found which appears to be identical 

 with streptococcus pyogenes." Baumgarten believes 

 these germs to be varieties of the streptococcus pyog- 

 enes. So that at present there seems to be no good rea- 

 son for doubting that this is the specific infectious agent 

 in scarlet fever, and enters the system by the mouth and 

 nasal passages. 



The streptococcus pyogenes is the specific germ in our 

 severe cases of blood poison, and cannot be identified 

 from the streptococus of erysipelas, but bacteriologists 

 observe that the effects produced by them are somewhat 

 different, as proven by the inoculation of the lower ani- 

 mals with artificial cultures of these germs. They are 

 spherical in form, with a mean diameter of 1-35,000 of 

 an inch. They multiply freely at ordinary room temper- 

 ature, 60° to 70° F., but more so at blood heat. Ther- 

 mal death-point is 130° F. This is also called the chain- 

 coccus, on account of the arrangement in more or less 

 elongated chains. Its peculiarity is to extend rapidly 

 along the lymph spaces and lympthatic vessels ; and if it 

 commences about the hand it extends up the arm, and 

 may cause progressive phlegmon, and often death, if 

 radical measures are not taken to prevent it. 



In this connection, attention may be called to the Hy- 

 drozone of Marchand as a specific for these diseases. 



