64 BACTERIOLOGY. 



In the spore, resting, or permanent state, as it is vari- . 

 ously called, no evidence of life whatever is given by the 

 spores ; though as soon as the conditions which favor 

 their germination have been renewed these spores de- 

 velop again into the same kind of cells as those from 

 which they originated, and the appearances observed in 

 the vegetative or growing stage of their history are 

 repeated. 



Multiplication of spores, as such, does not occur ; they 



FIG. 6. 



bed 



a. Bacillus subtilis with spores. 6. Bacillus anthracis with spores, c. Clos- 

 tridium form with spores, d. Bacillus of tetanus with end spores. 



possess only the power of developing into individual 

 rods of the same nature as those from which they were 

 formed, but not of giving rise to a direct reproduction of 

 spores. 



When the conditions which favor spore-formation 

 present, the protoplasm of the vegetative cells is seen 

 to undergo a change. It loses its normal homogeneous 

 appearance and becomes marked by granular, refractive 

 points of irregular shape and size. These eventually 

 coalesce, leaving the remainder of the cell clear and 

 transparent. When this coalescence of highly refrac- 

 tive particles is complete the spore is perfected. In 

 appearance the spore is oval or round, and very highly 

 refractive glistening. It is easily differentiated from 

 the remainder of the cell, which now consists only 



