54 THE GERMINATION OF THE ENDOSPORE 



but gives rise to horse-shoe chains .(Fig. 26), which only separate into their 

 individual members when the spore membrane has become swollen and flaccid. 



FIG. 24. Bacillus subtilis. 

 Spore germination. 



a. ripe spore ; l>. placed in a nutrient solution, 

 the refraction disappears ; e. enlargement 

 begins ; rf. the equatorial fissure is formed 

 and the young germ begins to escape ; e. in 

 the npper row the central portion of the 

 germ is just protruding, in the lower row 

 one pole is already freed ; /. the young rod 

 is at liberty ; g. it grows to its normal size ; 

 /i. reproduces by subdivision. Extra long 

 cells are seen at g and h in the lower row. 

 (After J'razmoirski.) Magu. IO-JQ. 



FIG. 25. Bacillus megatherium. 

 Spore germination. 



//]. two dried ripe spores enclosed 

 by the walls of the mother-cell. 



7; 2 . the same spores after forty- 

 five minutes' immersion in a 

 nutrient solutiou. 



/, /. the spore contents have in- 

 vested themselves with a new 

 membrane and are escaping 

 from the old capsule. 



m. two full-grown rods. 



(4fter 1)e Bar;/.) Magu. 600. 



FIG. 26. Bacillus subtilis. 

 Impeded germination. 



1. Cells with ripe spores causing 

 the mother-cell walls to bulge. 



2. Commencement of spore ger- 

 mination, capsule fissured equa- 

 torially. 



3. Ordinary unimpeded escape of 

 the germ. 



4. Exit somewhat impeded, one 

 pole being eventually liberated. 



5. Both poles of each germ re- 

 main fixed; germ divides into 

 two cells. 



(After lit liar a.) Magn. 600. 



FIG. 27. Spirillum endoparagogicum. 

 Spore germination. 



A, purely vegetative cells in brisk motion. 



B, three spirilla with four to six spores, those 

 in the central cell being ripe. 



D, mother-cell with germinating spores, from 

 which proceed 



E, branched forms, subsequently dismembered 

 into single cells. 



C, moribund spirilla, one with three spores. 



(After Sorokin.) Magn. 1375. 



The time occupied by Bacillus subtilis in germinating is, according to 

 Pra^mowski, generally 3-4^ hours at 3o-35 C., but frequently much longer. 



