HERBERT C. WARD 7 



ism should be included among the bacteria. Douglas and Distaso/ however, working 

 with a capsulated bacillus easily cultivated by them from cases of respiratory in- 

 fections, were able to stain successfully certain cellular uaiits closely resembling true 

 nuclei. 



Recently Gutstein,^ by staining methods, has made out a differentiation of the 

 bacterial cytoplasm into ectoplasm and endoplasm. Tn the endoplasm he finds a 

 macronucleus and a micronucleus. The ectoplasm of the gram positive bacteria Gut- 

 stein^ later has shown to contain a basic ground substance demonstrable by malachite 

 green and tannin, and an acid body demonstrable by Victoria blue. This acid sub- 

 stance Gutstein regards as a lipoid. Somewhat similar observations have been made 

 by Churchman-' in this country in his valuable studies on the gram reaction. He has 

 found that Bacillus anthracis consists of two distinct parts, a gram positive cortex 

 and a gram negative medulla. The term "cortex" as used by Churchman is equivalent 

 to ectoplasm and the term "medulla" to endoplasm. The cortex may be removed by 

 exposure to acriviolet or gentian violet and sometimes by hydrolysis in distilled 

 water. The material lost is probably protein in character since the Berkefeld filtrate 

 of a suspension of Bacillus anthracis exposed to gentian violet gives a positive nin- 

 hydrin test. Bessubetz^ believes that the bodies inside bacteria and demonstrable by 

 the use of the Giemsa stain are true morphological nuclei. Similar conclusions have 

 been reached by Schumacher*' on the basis of chemical reactions. 



In view of the recent investigations on the internal structure of the bacteria we 

 can only say that while true morphological nuclei cannot be regarded as definitely 

 proved, material giving the staining reactions of chromatin may be found in a great 

 many different bacteria. In stained specimens this chromatin is sometimes agglomer- 

 ated in masses which resemble the nuclei of plant and animal cells. 



CAPSULES 



Various new methods for the demonstration of capsules have been devised during 

 the past few years and our ability to fix and stain these structures has been consider- 

 ably enhanced. In addition to these newer staining methods a number of investiga- 

 tions have been made in regard to the chemical composition of the capsular substance. 

 It should be noted that these investigations relate to the capsules of the true encapsu- 

 lated bacteria like the pneumococcus, the Friedlander bacillus, and to certain intes- 

 tinal organisms like Bacillus coli and not to saprophytic bacteria. Such saprophytes 

 as Bacillus suhtilis and Bacillus mesentericus under certain circumstances are provided 

 with beautiful capsules, and it is certain tiiat a great many different species may have 

 a capsular material deposited about them under environmental stimuli. With the or- 

 ganisms mentioned above capsules form an integral part of the bacterial cell. With 

 such species as the Friedlander bacillus Toenniessen^ has shown that the capsule is a 



' Douglas, S. R., and Distaso, A.: Ceniralbl.f. BakterioL, 63, i. 191 2. 



'Gutstein, M.: ibid., 95, 357. 1925. 3 Gutstein, M.: ibid., p. i. 1925. 



* Churchman, J. W.: Proc. Soc. Exper. Biol. iT Med., 24, 737. 1927. 



sBessubetz, S. K.: Ceniralbl.f. BakterioL, 96, 177. 1925. 



^Schumacher, J.: ibid., 97, 81. 1926. 



' Toenniessen, E.: ibid., 65, 23. 1912; ibid., 85, 225. 1921. 



