262 , The Unity of the Organisin 



studies of Bacillus hiltschlii, and the latter making use of 

 the bacteria as one illustration of his now well-known chro- 

 niidial network theory. 



Another view, proposed by Biitschli in 1890 and since 

 favored by several students, is that the whole bod}'^ of the 

 bacterium is equivalent to the nucleus of a typical cell. A 

 recent strong advocate of this view is Vladislav Ruzicka. 

 This author defends the theorj^ mainly on the evidence he 

 believes he has obtained that bacteria as well as mammalian 

 red blood corpuscles, familiar examples of non-nucleated 

 cells, resist digestion in gastric juice in the same way as do 

 the nuclei of t3'pical cells. 



Still another group of authors believe nuclei not funda- 

 mentally different from typical nuclei are present in bac- 

 teria. But again as soon as this view is examined in detail, 

 the widest possible differences are found as to the criterion 

 of what a nucleus is, and as to what objects in the organism 

 are nuclei. Arthur Meyer, one of the most conservative 

 supporters of this general view, believes he is able to demon- 

 strate a nucleus in several genera and species, in the form 

 of a minute granule more highly light-refracting than the 

 surrounding cytoplasm as seen in the unstained condition, 

 and reacting differently from all other substances toward 

 various stains. It is most readily seen in the spore stage 

 of the organism's life, and has so far been demgnstrated in 

 only a comparatively few species, taking the bacterial group 

 as a whole. Dobell on the other hand, believes himself justi- 

 fied, after an examination of many species belonging to 

 nearly the whole bacterial series, in declaring, "I think I 

 may fairly claim from what has been pointed out in the 

 preceding pages that not only do my own observations fur- 

 nish conclusive evidence with regard to the nucleus in bac- 

 teria, but that in almost every case in which careful investi- 

 gation has been made by others, the results are not 

 inconsistent with mine," his results being that "tlie Bacteria 



