SPORES 45 



somewhat like the' chromosome of higher cells as a " center of 

 attraction" so that the protoplasm gradually collects around 

 it. The spot disappears or is enclosed in the collected proto- 

 plasm. This has evidently become denser as it is more 

 highly refractive than before. In time all or nearly all of 

 the protoplasm is collected. A new cell wall is developed 

 around it which is thicker than the cell wall of the bacterium. 

 This thickened cell wall is called the "spore capsule." 

 Gradually the remnants of the former cell contents and the 

 old cell wall disappear or dissolve and the spore becomes 

 "free" (Fig. 24). 



. _. . -,„aller oval bodies in the middle of the field are free spores. 



ii uiiu opv/j.e is placed in favorable conditions the proto- 

 plasm absorbs water, swells, the capsule bursts at some 

 point, a cell wall is formed and the bacterium grows to 

 normal size and divides, that is, it is an active growing cell 

 again. This process is called "germination" of the spore. 

 The point at which the spore capsule bursts to permit the 

 new cell to emerge is characteristic for each kind of bac- 

 terium. It may be at the end when the germination is said 

 to be polar (Fig. 25). It paay be from the middle of one 

 side which gives equatorial germination (Fig. 26). Rarely it 

 is diagonally from a point between the equator and the pole, 

 which type may be styled oblique germination. In one or 

 two instances the entire spore swells up, lengthens and 

 becomes a rod without any special germination unless this 

 type might be designated bi-polar. 



Spores are most commonly oval or 'elliptical in shape. 



