Organisms Consisting of One Cell 261 



their existence is conclusive proof that the main body of the 

 organisms is not structureless ; and almost conclusive proof 

 too, when the extreme minuteness, and hence difficulty of 

 observation is taken into account, that not only are they 

 not structureless, but that their structure would amount, 

 could it be seen as readily as that of larger organisms, to a 

 very considerable degree of complexity of organization. 

 And this, be it noticed, follows even though considerable 

 portions of the body substance, especially in some stages of 

 the individual life cycle, still look structureless or homo- 

 geneous mider the highest magnifications and best conditions 

 of lighting and staining. Although this phase of our dis- 

 cussion does not require us to go farther into the inter- 

 pretation of the structure thus generally looked at, it is 

 nevertheless desirable to attend to the subject a little more 

 specifically. 



{c) The Question of a Nucleus in Bacteria 



We may first speak of the present status of the nuclear 

 problem as touching the bacteria. The most prevalent view 

 still is that the bacterium is a non-nucleated cell, if by 

 nucleus one is to understand the organ that goes by that 

 name in higher plants and animals. But there is plenty of 

 dissent from this view, and seemingly this is growing in 

 volume. Those who believe in the presence of a nucleus are 

 still far from agreement as to what shall be regarded as this 

 organ. One group of observers speak of a "diffuse nucleus," 

 the idea being that certain of the granules mentioned above 

 are chromatin or something close of kin thereto ; and since 

 according to a widely prevalent theory, this is the most es- 

 sential constituent of the nucleus in the cells of higher or- 

 ganisms, they believe it justifiable to consider bacteria nu- 

 cleated. Schaudinn and Richard Hertwig are prominent 

 advocates of this view, the former basing it primarily on his 



