82 THE DISEASES OF DOMESTIC ANIMALS. 



no independent movements, but simply display the well-known mo- 

 lecular trepidation. 



The function of spherical bacteria has been determined to be 

 zymotic ; that is, ferment-producing. According to Cohn, they do 

 not take part in the production of putrefying processes. 



While the above includes a distinct form of germ-life, there is 

 no question that the spores of some other forms of germ-life, viz., 

 bacillus, give no distinguishing means by which to separate them 

 from spherobacteria, except the results of experimental cultivation ; 

 as the Bible says of men, " By their fruits shall ye know them." 



There is but one genus of the spherobacteria, viz., " micrococcus." 

 They are described as cells, colorless or scarcely colored, very small, 

 globular or oval, forming by transverse division, filaments of two or 

 several articulations in the form of a chaplet, or united in numerous 

 cellular families, or in glutinous masses, all motionless. This genus 

 is divided into three groups : 



Micrococcus chromogenes. 



Micrococcus zymogenes. 



Micrococcus pathogenes. 



The first groups are again distinguished as to the solubility or 

 insolubility of the coloring-matter, and are found upon vegetables, 

 milk, etc. 



The second group contains but one variety of special interest to 

 us, viz., M. ureal, found in urine, where it transforms the urea into 

 carbonate of ammonia (Pasteur). 



The pathogenetic micrococci are of so much more importance 

 that we must give them particular attention. 



They are spherical bacteria, which are found in affections of a 

 contagio-infectious nature, such as M. vaccinae, being very small, 

 appearing isolated or in pairs in recent vaccine virus, and in the 

 pus of variola-pustules. They are looked upon as the active prin- 

 ciple of vaccine virus. 



M. diphtheriticus. — Granular ovoid cells, isolated, or more fre- 

 quently united in pairs, or in a chaplet of four to six cells, some- 

 times multiplying in colonies, and extending themselves in all the 

 complicated tissues, decomposing and destroying them. 



M. septicus. — Little round, motionless cells, crowded in masses 

 or united in chaplets ; found in the secretions of wounds in cases of 

 septicaemia, as zooglsea in callous ulcers, as isolated cells, united in 

 pairs, or chaplets, in the serum of epidemic puerperal fever, and 

 in all tissues, vessels, etc., in pyaemia and septicaemia. 



Many others have been found and given specific names, espe- 



