Slime Moulds, Bacteria, and Yeasts. 257 



to determine the details of their construction. They are 

 enveloped by an extremely thin translucent membrane. 

 Whether they have nuclei is a question which is still in 



t 1% ti 



', v tv- I 



'-/ 



t l> 



* V V 



c FIG. 133. d 



a, yeast plants, some of them budding; b, micrococci (singular, micrococcus) from 

 the air; c, Bacillus subtilis, showing internal spore-formation; d, bacilli (singu- 

 lar, bacillus) of Asiatic cholera, with motile flagella. Photomicrographs X 740. 

 After GUNTHER. 



doubt. It is thought by some that the bulk of their bodies 

 is made up of nuclear material. 



153. Methods of Reproduction. Bacteria reproduce by 

 division, one becoming two, two four, and so on. Asexual 

 spores are also formed, either by the ordinary cells pro- 



