CULTURES IN LIQUID MEDIA. 63 



of culture fluid, attached to a thin glass cover and suspended over a 

 circular excavation ground out of a glass shoe, is very useful. 

 Such a drop culture may be left under the microscope and kept 

 under observation for hours or days. 



pieveat the inoculation of the drop of culture liquid with any other 

 bacteria than those which are to be studied. 



The smiJMdk form of moist chamber for drop cultures consists of 

 an ordinary glass shoe having a concave depression, about fifteen 

 in diameter, ground out in its centre. This and the thin 

 r. having been sterflhed by exposure in the hot-air oven at 

 ISO CL for an hoar or more, or by passing them through the flame 

 of an alcohol lamp, are ready for use. The cover glass is held in 

 sterile forceps, and a little drop of the culture fluid containing the 

 bacterium to be studied is transferred to its centre by means of the 

 pfatjnmn loop heretofore described. It is best to spread the drop 

 out as thin as possible, and it may be inoculated, from a pure cul- 



36) after it has been placed upon 

 he hollow place in the glass 

 to prevent the entrance of air and attach 

 EtOa VMBBIM HOMnd (he mtuspm of flba 



by attaching a glass 

 to the centre of a glass elide 



by 



In Ranvier s moist chamber there is a central eminence sur- 

 by a groove ground into the glass slide, and the drop of 



above. Tins affords a more satisfactory view under the micro- 



TheA*tkor*Cltri> JfefltodL In a paper read at 



1681, the writer described a method of conducting culture 



