MATURE SPORES. 27 



in swamp-water and studied by him, but unfortunately they were not 

 cultivated in pure culture. (Bacillus De Baryanus, Solmsii, Peroni- 

 ella, macrosporus, limosus). His observations were as follows: With- 

 out loss of motion, the end of the bacillus swells somewhat and be- 

 comes faintly greenish. Now the whole content of the swollen spot 

 contracts into a shining spore of a bluish-green color and highly 

 shining. 



Mature spores are arranged in the most important 

 varieties in the following manner (Fig. 9): The spore lies 

 inside of an unexpanded short bacterial cell (a), or at the 

 extreme end of a bacterial cell (c), or inside of a spindle- 

 formed bacterial cell, bulging at its center (d), or, finally, 

 the spores occur in a row in a thread, formed from short 

 cells, each cell containing a spore (6). 



V tf 



Fig. 9. Types of spores. 



The spores, before germination occurs, are usually free 

 (an exception occurs in spirillum endoparagogicum), often 

 show an indistinct border, always lose their luster, become 

 somewhat thicker, and rarely also longer. Usually after 

 one, two, or three hours the spore membrane bursts and 

 the young rod, sometimes suddenly, sometimes slowly, 

 presses itself through the rent. The germination in an= 

 thrax is polar /, e. , the young rods leave the spore capsule 

 at or near the pole (Fig. 10). In other varieties (B. 

 subtilis, mycoides, megatherium) the escape of the rod is 

 equatorial (Fig. 10, a). Burchard describes also a bipolar 

 and oblique mode of escape. According to the observa- 

 tions of Bunge (Fort, der Med., xm, 813, 853), in both 

 the polar and equatorially germinating varieties, single or 

 many individuals always present an oblique outgrowth. 



