138 BACTERIOLOGY. 



about liquefaction, it will soon be discovered that this 

 result is by no means of the same appearance for all 

 organisms. Some organisms cause a liquefaction which 

 spreads across the whole upper surface of the gelatin 

 and continues gradually downward; again , it occurs in 

 a funnel-shape, the broad end of the funnel being upper- 

 most and the point downward, corresponding to the 

 track of the needle. At times a stocking- or sac-like 

 liquefaction may be noticed. (See Fig. 34.) 



NOTE. Obtain a number of organisms from differ- 

 ent sources in pure cultures by the method given. Plant 

 them as pure cultures, all at the same time, in gelatin 

 preferably gelatin of the same making retain them 

 under the same conditions of temperature, and sketch 

 the finer differences in the way in which liquefaction 

 occurs. 



