KM ( )K I IS. 



Ill 



fermentation tubes, since records made with these pencils will bear streaming steam. 

 An inexpensive black pencil which writes on clean glass very readily and bears 

 steam well (even better than Faber's) may be made by stirring into melted beeswax 

 enongh lamp-black to make a thick-flowing liquid (as thick as will flow). This is 



poured into molds made by wrapping writ- 

 ing paper, in several turns, around a lead 

 pencil or thick glass rod, tying near one end, 

 removing the rod, squeezing the other end 

 flat, turning over its edge, and fastening this 

 flattened end in a split stick or clamp. The 

 paper should be retained as a cover, the string 

 being removed and the loose edge pasted 

 down. A dozen such pencils may be made 

 at a cost of 10 cents. In the absence of such 

 pencils, flasks and fermentation tubes may 

 be distinguished in the steamer by dropping 

 over the neck different-sized rubber bauds or 

 different numbers of the same kind of band, 

 or by writing with a lead pencil the number 

 of the stock on a square of letter paper, cut- 

 ting a hole in its center and slipping this 

 over the neck of the flask or tube. When 

 the steaming is over, the regular labels should 

 Fi % * be pasted on or the stock number written on 



with the proper pencil. 



All plate cultures and all subcultures made on a given day, 110 matter of what 

 organism, are numbered serially, beginning with i. These are i, 2, 3, etc., of that 

 particular day. Those of any other day are also numbered i, 2, 3, etc. The writer 



Fig. 97* 



usually numbers his plates I, II, III, etc. Labels may be pasted on the covers of the 

 Petri dishes, or all may be done with the glass pencil. Cultures in tubes subject to 

 frequent handling and likely to be needed for some time should have gummed-paper 

 labels written in ink. The above transcripts from labels on four test-tube cultures 



*l"i<:.. cy > Labels from tcst-tulie culture-;. 



;. 97. Wooden lalcrls from inoculated plants. 



