THE FISSION PLANTS. 69 



to the cover glass. Be careful not to burn. Float the 

 cover glass, prepared side down, on a solution of gentian 

 violet for ten minutes or longer. Wash by immersing in 

 water, let it dry in air, and pass through the hot air above 

 a flame. Invert the cover glass on a small drop of Canada 

 balsam on a slide. Preserve as a permanent mount. 



4. Examine a bit of the pellicle formed on the Pasteur's 

 solution and also some of that on the solution of vegetable 

 matter. Observe that the Bacteria are motionless and 

 that they are imbedded in a transparent, gelatinelike 

 mass. 



5. Allow a piece of raw fish or meat to stand in a vessel 

 of water for some days. Examine from time to time for 

 Bacteria. The succession of forms that will appear will 

 afford good material for instructive study. Among other 

 forms, numerous motile spiral forms will be found, 

 Spirilla and Spirochsetse. Draw some of the larger forms. 



6. In a similar way study the Bacteria that will surely 

 be found in any other putrefying substances. 



7. After Bacteria have been found in abundance in 

 the Pasteur's solution (see Number 3), place a little of 

 the solution in each of two test tubes. Wrap one of the 

 tubes in thick, opaque paper. Set the two tubes aside 

 for two or three days or more, with all other conditions 

 the same for both. Determine whether light is necessary 

 for the growth of the Bacteria. 



References for Reading. Parker's "Elementary Biology," pp. 82- 

 94 ; Bidgood's " Elementary Biology," pp. 59-71 ; Klein's " Micro- 

 Organisms and Disease " ; Woodhead's " Bacteria and their Products " ; 

 Huxley and Martin's "Practical Biology," pp. 408-414; Vines' " Text- 

 Book of Botany," pp. 280-283 ; Goebel's " Classification of Plants," 

 pp. 24-27; Sachs' "Physiology of Plants," pp. 384-386; Schenck's 

 " Manual of Bacteriology " ; Strasburger and Hillhouse's " Practical 

 Botany," pp. 221-224; the author's "Practical Methods in Micros- 

 copy," 2d ed., pp. 171-197; Strasburger, Noll, Schenck, and Schim- 

 per's " Lehrbuch der Botanik," pp. 269-272. 



