AGRICULTURAL BACTERIOLOGY. 



is called binMing and the yeasts are consequently called the 

 Budding fungi. The importance of yeasts in the great fermen- 

 tative industries, so closely related to agriculture, is well known. 

 3. Schizomycetes. (Fission fungi. Bacterial) 

 These plants are also microscopic. They differ 

 from yeasts in being smaller and somewhat dif- 

 ferent in shape, but chiefly in their method of 

 reproduction. Instead of forming buds they 

 multiply by lengthening somewhat and then 

 dividing into two equal halves (Fig. 3). This 

 process is called fission and hence these organ- 

 isms are the Fission fungi. This group includes 

 the organisms which have for the last quarter of a century 

 been known as Bacteria. It is with these that we are chiefly 

 concerned in this work. 



FIG. 3. 



00 



oo 



CO 



Bacteria, show- 

 ing method of di- 

 vision by fission. 



II. FORM AND CLASSIFICATION OF BACTERIA OR 

 SCHIZOMYCETES. 



Under ordinary conditions Bacteria are extremely simple in 

 form. Long ago they were compared to billiard balls, lead 

 pencils and cork screws (Fig. 4), and even the most careful 



FIG. 4. 



General shape of bacteria : a, spheres ; b, rods ; c, spirals. 



work with the modern microscope has hardly improved upon 

 this somewhat crude but striking comparison. Nearly all 

 bacteria atv either spheres, cylindrical rods of greater or less 

 length, or spiral rods. In M'/.C they are inconceivably minute, 



