BACTERIA. 51 



Nucleus. The question of whether or not the bacteria possess a 

 nucleus is one that has engaged the attention of bacteriologists and biolo- 

 gists for some time. It is very certain that the bacteria do not possess a 

 nucleus in the ordinary sense in which the term is used in animal and plant 

 histology. There are several different views in regard to this matter. 

 One is that the bacterial cell is largely nucleus, and attention has already 

 been called to the fact that cytoplasm stains with what are known as nu- 

 clear stains. But this is not convincing proof that the material of the bac- 



FIG. 31. i and 2, Bacillus mycoides; 3, B. megatherium; 4, B. radicosus; 5, B. 

 oxalaticus. (After Bohuslaw Rayman and Karel Kruis Jrom Guilliermowd review, 

 Bull. Inst. Past.) 



terial cell is nucleus. Were this true, however, it would fit in very nicely 

 with the theory of evolution, since evolutionists are desirous of finding a 

 group of organisms with the cell reduced to its simplest form. Another 

 idea is that the nuclear material is widely distributed throughout the 

 bacterial cell and not concentrated into one structure (Fig. 31). Such a 

 view as this is in harmony with Biitschli's work. Zettnow appears to have 

 stained nuclei. Another class of thinkers, in which Alfred Fischer is 

 prominent, believe that the bacterial cell is without a nucleus. This is 

 borne out, to their minds, by the findings that the bacterial cell plasmo- 

 lyzes, that the nucleus of higher animals and plants does not; therefore 

 the bacterial cytoplasm is not nuclear. 



FLAGELLA. The flagella are protoplasmic threads and, undoubtedly 



