Til E I. kCTERIOLOGY OF BEE DT3E \-i 58. | 



These plants, then, constitute an invisible flora, which we can see onlv 

 by the use of a microscope of \ciy high magnifying power. The 

 morphology, or the structure, including form and size, is principally 

 of two types, rod-shaped or cylindrical and round or spherical. The 

 size of bacteria varies. Those which are rod shaped usually measure 

 from 1 to 3 6 microns in length and Prom one-half to I micron in 

 diameter. A micron is the unit of measure for very small objecl 



and is equivalenl to •..-,,' of an inch. For example, if a single bac 



terium of the rod form measures 2 microns, it would take L2,i 500 

 placed end to end to measure 1 inch in length. The spherical bacteria 

 or cocci have about the same diameter as the rod shaped one . 



Bacteria grow or multiply after a manner called fission; that is, 

 after increasing in size they become constricted in the middle, which 

 constriction finally severs the rod completely, and we then have two 

 bacteria where there was but one before. Under favorable condition 

 for growth, each bacterium divides by fission every twenty minutes, 

 or, in other word-, gives rise to three generations in one hour. Such 

 being their marvelous rate of increase, a little calculation will demon- 

 strate that countless million- may be formed in a short time under 

 favorable conditions, which are proper temperature, moisture, food 

 in correct proportions, and the absence of much light. The tempera- 

 ture most favorable for the growth of a species of bacteria which is 

 able to produce a diseased condition in animals is approximately th 

 temperature of the animal which is affected by such species. Mois- 

 ture is universally uecessary. The food must not be too concentrated. 

 Light inhibits the growth of bacteria. Direct sunlight is bacteri- 

 cidal : that is, it kills bacteria. 



Many species produce spore- when the condition- are not favorable 

 for the multiplication of bacteria. These are small bodies formed in 

 the bacteria (probably never more than one in a single bacterium) 

 which arc somewhat comparable to the grain in wheat and corn. 

 These spores constitute a resting stage and usually also a very resist 

 ant stage, for high temperature and strong disinfectant solutions are 

 accessary to kill them. It is these spores which probably make the 

 control of the bee diseases more difficult. When the spore- again gain 

 access to a suitable ".-oil.*" for example, the body of an animal, they 

 germinate and a new growth take- place a- before. 



Many species of bacteria have the power to move when they are in 

 a. liquid medium, while other- do not. This ability t<» move is due to 

 long, slender processes, which we call flagella, extending from the 

 body of the bacterium. 



THE DISTRIB1 I i<>\ OF !'. \« Tia.'l \. 



Bacteria are very widely distributed. Everyone is familiar with 

 the very wide distribution of the higher members of the plant king- 



