v] METHODS OF INOCULATION hj 



the growth of the individual bacilli fixed in the set gelatine 

 into threads and the formation of the characteristic colonies 

 made up of curved and convoluted threads. Equally in- 

 teresting is it to watch the formation of colonies by the 

 proteus vulgaris or proteus Zenkeri, the " swarming '' of them, 

 and the manifold sprouting of threadlike outgrowths ; or 

 the gradual formation of bright globules and their enlarge- 

 ment into the characteristic oval spores in the threads of 

 bacillus anthracis or of hay bacillus, and their ultimate 



Fig iq —A Glass Cell, foe Observing under the Microscoi'e the 

 Progress of Growth of Micro-organisms. 



The upper figure shows the cell In perspective ; the lower figure in profile or cross 

 section. 



A. Glass slide. 



B. Cov^r-glass. ,, .. , , . 



C. Glass ring forming the wall of the chamber. 



P. Drop of nourishing material in which the micro-organisms grow. 



discharge and disintegration of the baciUi themselves. All 

 these points can be directly studied by intermittent obser- 

 vation in the above preparations extending over several 



days. 



5. Baderioscopic Examination of Water.— M-o-A waters 

 contain bacteria of some kind, sometimes in great numbers 

 without altering the limpidity of the water, at any rate not 

 for the unaided eye or the ordinary tests of transparency. 



In order to directly demonstrate the bacteria, the water 



