ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 495 



which is not too acid. lu a gramme of bread there may be 500,000 

 of these bacilli. They are not destroyed in the stomach ; the spores 

 and rods both resist twenty-four hours' submersion in artificial gastric 

 juice. In the digestive canal of man they find substances extremely 

 rich in albuminoids and in cooked starch ; and, in consequence of 

 their power of living in both acid and alkaline media, they contribute 

 greatly to the process of digestion. 



Bacillus panificans is the bacterium of " ropy " bread, which is 

 produced when the dough is insufficiently acid, and results from the 

 transformation of the starch into a substance resembling erythro- 

 dextrin. The " rising " of bread is the result of the disengagement of 

 carbonic acid caused by this organism. 



Bacillus of Syphilis.* — Dr. Matterstock has endeavoured, by a 

 large number of experiments, to determine the true microbe of 

 syphilis. He finds uniformly, though always in small quantities, the 

 bacillus described by Lustgarten ; f but this bacillus is subject to so 

 great variation that its diagnostic value is very small. Not only 

 does it vary greatly in the length and thickness of the rods, but in 

 the configuration of the rods themselves, some being straight and 

 others with eel-like curves; the length is in some cases ten times 

 that in others. As many as ten different forms were observed, which 

 may possibly be stages in the development of the same organism. 



De Bary's Lectures on Bacteria.:}: — Prof. A. de Bary publishes, 

 in a collected form, a series of lectures given at different times, on 

 bacteriology, which give a good summary of the present state of our 

 knowledge of the science. The terms " coccus," " bacterium," &c., 

 are used throughout simply to designate forms of growth. 



Garbini's Guide to Bacteriology. §—Sig. A. Garbini publishes a 

 complete guide to bacteriology in accordance with the present state of 

 the science. It treats of the necessary instruments, apparatus, and 

 reagents, including staining-methods, the various modes and materials 

 for culture, a description of special methods of investigation, and the 

 morphology and classification of the known forms of Schizomycetes, 

 in which the system of Cohn is followed. The work is illustrated by 

 woodcuts. 



* SB. Phys.-med. Gesell. Wiirzburg, 1885, pp. 65-73. 



t See this Journal, v. (1885) p. 539. 



X De Bary, A., ' Vorlesungen uber Bakterien,' 146 pp. (18 figs.), 8vo, 

 Leipzig, 1885. 



§ Garbini, A., ' Guida alia Bacteriologia,' xv. and 145 pp. (34 figs.), Svo, 

 Verona, 1886. 



