GOX'iTvinUTIOXS TO THli CYTOLOiiY OF THE BACTERIA. 407 



of simple constriction. An ordinary form of nucleus was not 

 found. 



Xakanishi (1901) describes nuclei in a large number o£ 

 Bacteria (Cocci, Bacilli, Spirilla) stained with metlijdene 

 blue, either intra-vitam, or after fixation with formol vapour. 

 He finds minute spherical nuclei in Cocci ; nuclei in the form 

 of a granule, rodlet, or filament in Bacilli; and granular or 

 filamentar nuclei in Spirilla. He also finds nuclei in 

 spores. He gives an excellent account of his technique, good 

 figures, and strong evidence for the conclusion that the 

 structures he observed are really nuclei. His interpretations 

 have been unfavourably criticised by Ascoli (1901 a), Ficker 

 (1903), Preisz (1904), Meyer (1908), and others. 



Schaudinn (1902) inaugurated a new era in bacteriology by 

 studying cytologically the whole life-cycle of the gigantic 

 Bacillus biitschlii in the gut of the common cockroach. 

 He described a nucleus in the form of scattered granules of a 

 chromatic substance (chromidia) throughout the greater part 

 of the life-cycle. During spoi-e- formation the granules 

 arrange themselves in a spiral and finally become aggregated 

 into dense masses in the fully formed spore. A process 

 interpreted as a modified sexual act (autogamy) was dis- 

 covered. In the following year (Schaudinn, 1903) he 

 described analogous conditions in Bacillus sporonema, a 

 small marine organism. 



Meyer's jDupil Grimme (1902) has given a lengthy and 

 elaborate account of the chemical and staining reactions 

 of many different kinds of granules which occur in many 

 different Bacteria. After a discussion of the various kinds of 

 granules which he studied — especially the "metachromatic 

 granules ^' (" Volutanskugeln ") — he finally decides in favour 

 of the nuclear views of Meyer. The "nuclear" granules of 

 most other observers are probably not nuclei. (In connection 

 with these granules see also Guilliermond [1906, 1910, etc.], 

 Meyer [1904], Eisenberg [1910], etc.). 



Under the name Spirillum colossus, Errera (1902) 

 describes an enormous spirillar form. Darkly staining masses 



