286 ROMANCE OF LOW LIFE AMONGST PLANTS, 



myriads of exceedingly minute bodies, of which pre- 

 viously only vague suspicions were entertained. 

 Notwithstanding their minute size, these microbes 

 are now known to be important factors in health 

 and disease, so that, imperfect and incomplete as 

 our knowledge still remains, medical authorities have 

 been compelled to admit their existence and influence 

 in many epidemics. That objects so minute as to 

 be invisible to the naked eye should produce such 

 disastrous results is sufficient to invest them with an 

 atmosphere of romance, and the names of Bacteria 

 and Bacilli, which but a few years since were almost 

 unknown, have become household words. These 

 microbes appear, under a high power of the micro- 

 scope, as small cells of a spherical, oval, or cylindrical 

 shape, sometimes detached, sometimes united in 

 pairs, or in chains or chaplets. So minute are they 

 that from five hundred to two thousand of them 

 must be placed end to end in order to attain the 

 length of a millimetre, which is not more than the 

 twenty-sixth part of an inch. 



It was about the year 1850 that the presence of 

 minute rods was observed in the blood of animals 

 which died of splenic fever, but it was^not until 

 1863 that they were suspected of being the cause 

 of the disease. At this time Davaine inoculated 

 healthy animals with the tainted blood, and ascer- 

 tained that a very minute dose would produce a 

 fatal attack of the disease, and the rods could be 

 discovered in enormous quantities in the blood. 

 This disease is generally inoculated by the bite of 

 flies, which have absorbed bacteria from diseased 



