BY OSCAR KATZ, PH.D., M.A. 915 



(b). in their mode of growth in solid 5-6 % nutritive gelatine 

 enclosed in test-tubes, or in other words, in the deportment of 

 their pure cultivation in this nourishing soil and under these 

 conditions. 



(c). in their pure cultivation on an oblique surface of 

 peptonised agar-agar broth or nutrient agar-agar (1) in test-tubes. 



Five specifically different forms of bacteria as yet have been with 

 certainty obtained from the water in question ; they are described 

 provisionally as Bacterium (Bacillus or whatever it may be) 

 A, B, C, &c, adopting the plan of Malapert-Neufville. (2) 



Of a few other bacteria the colonies of which from time to time 

 appeared on the gelatine-plates, it is more than doubtful that they 

 were contained in the samples of water employed. Firstly, they 

 were met with in mostly one colony each, and only very seldom ; 

 secondly, they made their appearance after the plates, for the 

 purpose of first examination, had already been in contact with 

 the air of the room ; lastly, they were found only at the surface of 

 the gelatine. These colonies showed themselves to be very 

 interesting, and I hope to return to them at the earliest 

 opportunity. 



Bacillus A. 



Microscopical Characters. Short rods of from -0015--0018 mm. (3) 

 in length and about *0008 in breadth; singly or in twos; extremities 

 rounded ; protoplasmic contents not thoroughly homogeneous, 

 inasmuch as the ends of the rods stain with aniline-dye better than 



(1) Agar-Agar, or Japanese isinglass, of good quality, is to be had 

 in packets of about J lb. at Chinese shops, George-street, Sydney. 

 According to a label referring to a sample of such vegetable isinglass in 

 the Technological Museum of Sydney, it is called " Kanten " "prepared 

 by exposing the jelly obtained from Gelidium corneum (Lamarck) 

 to the intense frost of a winter's night. It congeals and hardens 

 and may then be kept for a great length of time." So far as I am 

 informed there are more than this one species of seaweeds used for 

 preparing Japanese isinglass or agar-agar. A nutrient agar-agar of 1 % 

 withstands more than blood-temperature without becoming liquid, and is, 

 on account of this property and from the fact that it is not to be liquefied 

 by any bacterial growth, much used in bacteriological laboratories. 



(2) Loc. cit. 



(3) 1 mm. = '03937 inch ; "001 mm. = '0003937 inch. 



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