ARTHUR ISAAC KENDALL 231 



studying the chemistry of the cellular substance of the tubercle bacillus, claimed to 

 have identified a pentose among the constituents. This, if substantiated, would seem 

 to place this organism at least among the plants, because the animal nucleus con- 

 tains a hexose.' The presence of cellulose, and of hemicellulose, is still a matter of 

 discussion, with the balance of evidence as yet unfavorable, although Emmerling, 

 Winterstein,^ and others claim to have detected it in the substance of bacteria. On 

 the other hand, chitin, a polymer of glucoseamine^ found in the animal kingdom, 

 principally in the carapace of Crustacea, has been reported by several investigators. 

 This is quite important if true, because it leaves the bacteria in an ambiguous position 

 with reference to the usual chemical concepts of classification — having nuclear sub- 

 stance of plant affinity, and at the same time possessing chitin, usually regarded as 

 of animal origin, in their cell membranes. 



CAPSULAR CONSTITUENTS 



Certain kinds of bacteria, as pneumococci, pneumobacilli, the gas bacillus (Ba- 

 cillus welchii), and several occurring in the soil, are surrounded with mucoid envel- 

 opes. Acetic acid precipitates this mucoid substance in many instances, which has 

 led to the belief that the material may be true mucin. Recently Dochez, Avery, 

 Heidelberger, and others'" have isolated polysaccharides from the pneumococci, the 

 Friedlander bacillus, and other organisms which are not true mucins but which are 

 precipitated with the homologous-type sera in very high dilutions. These "species 

 specific" polysaccharides are very interesting and important both from the stand- 

 point of immunity and virulence. 



EFFECTS OF CARBOHYDRATE UPON THE CHEMICAL COMPOSITION OF BACTERIAL CELLS 



Cramer,^ Lyon,^ and others have published analyses which seem to indicate that 

 the presence or absence of utilizable carbohydrate in cultural media otherwise of the 

 same composition influences the relative amounts of nitrogenous substance, alcohol 

 and ether extracts, and ash quite materially. Just what significance is to be attached 

 to these data is problematical. They may, however, be of significance in view of the 

 fact that Dochez and Avery" found that the yield of the "species specific" polysac- 

 charides from type-II pneumococci increased from 3-4 to 35-40 gm. per 300 liters of 

 culture when glucose was added to the medium. 



CARBOLIGASE 



Mention should be made at this point of the important observation of Neuberg^ 

 that yeast is capable of bringing about syntheses of organic compounds in the presence 



' Jones, W. : Nucleic Acids, pp. 21, 29. 1924. 



^Emmerling, O.: Ber. d. dent. chem. Gesellsch., 32, 541. 1897; Winterstein, E.: Ztschr. f. phys. 

 Chemie, 21, 134. 1895-96. 



3 Viehover, A.: Ber. d. dent, botan. Gesellsch., 30, 443. 1912. 



■» See, for an excellent summary, Heidelberger, M.: "Immunologically Specific Polysaccharides," 

 Chem. Rev., 3, 403. 1927; Heidelberger, M., and Goebel, W. F.: /. Biol. Chem., 70, 613. 1926; also 

 chap. X in this volume. 



5 Cramer, E.: Arch.f. Hyg., 16, 151. 1893. ^Lyon, R. E.: ibid., 28, 30. 1897. 



'Neuberg, C, and Kobel, M.: Handb. d. biol. Arbeiismeth., Abt. IV, p. 625. 1927. 



