COXTIUBUTIOXS TO THE CYTOLOGY OF THE r.ACTEKIA. 397 



the most divergent views are lield regarding the various 

 structures present in the bacterial cell. He will find, for ex- 

 ample, regarding that most important of all cell-structures — 

 the nucleus, that all views regarding its existence are held — • 

 from that which tells him that there is no nucleus of any sort, 

 to that Avhich tells him that the whole cell is to be regarded 

 as a free nucleus. 



Now the reason for this divergence of opinion is not far to 

 seek. For many years the Bacteria have been entrusted to 

 the bacteriologists, and only an occasional botanist or zoologist 

 has ventured to poach on their preserves. Yet to the bacterio- 

 logists, the Bacteria are but a means to an end — they study 

 them in order to cure a cold or make a cheese. Modern 

 bacteriological methods are excellent and adequate when 

 applied to medical diagnosis or industrial needs, but they are 

 inadequate wlieu applied to a study of the Bacteria themselves.^ 

 It is for this reason that professed bacteriologists possess such 

 remarkably diverse opinions regarding the normal structure 

 of Bacteria, and it is for this reason also that what little is 

 definitely known of their cytology is due largely to the labours 

 of a few zoologists and botanists. The bacteriologists are, of 

 course, not to blame for this. Their aims are wholly different 

 from those of the protistologist or cytolog'ist. It is from 

 these that our knowledge of the structure of Bacteria inust 

 come. 



The great majority of Bacteria which have been described 

 have taught us nothing concerning the internal structure of 

 the bacterial cell. Xearly all the pathogenic forms are of 

 exceedingly small size ; and in addition to this great dis- 

 advantage they have mainly been studied after fixing and 

 staining in the usual bacteriological manner, which renders 

 them worthless for cytological purposes. It is desirable, in 

 the fii-st place, to study the largest and most easily investigated 



^ The trutli of this can easily be seen by anyone who will consult the 

 vast nnmljer of text-books on bacteriology which are in current use. 

 In the majority of these, the cytology of Bacteria is not noticed at all., 

 or else dismissed with a few inaccurate remarks made at random. 



