142 BACTERIOLOGY. 



cover-glasses from a flat surface, and that, in staining, no 

 c?,pillary drainage exists. Moreover, owing to the point- 

 contact, the specimen can always be washed perfectly 

 clean, without leaving the unsightly spot so often caused 

 by a broad pointed pair of forceps. 



The above forceps can be obtained, supplied with a 

 clasp (Fig. 20 &), as in the case of Ehrlich's forceps. In this 

 form, it will be found to be superior to the awkward, heavy 

 Cornet forceps, or its several modifications. 



Examination of Living Bacteria.' 



This is intended to show the bacteria in their natural 

 condition. The study of an organism is manifestly incom- 

 plete, if the examination of the living form is omitted. A 

 great deal of information can thus be acquired, which might 

 otherwise be overlooked. Care should be bestowed espec- 

 ially upon the form and grouping of the cells, the presence , 

 or absence of motion, the appearance of the protoplasm, 

 whether colored or granular, the presence of sporogenic 

 granules, and of spores. Obviously, the process of cell di- 

 vision, spore formation, and germination can only be ob- 

 served on living organisms. 



The simplest method for examining living bacteria is as 

 follows: A little of the growth is picked up on the end of 

 a sterile, cooled platinum wire (Fig. 28 e), which is then 

 touched, several times, to a drop of water on a glass slide. 

 The drop of water should, as a result, show a visible cloud- 

 iness. It is then covered with a glass slip, and examined 

 under the microscope. When this procedure is followed, it 

 is desirable that the drop of water taken be so small that it 

 will not float the cover-glass. 



The examination of the living organism on an ordinary 

 glass slide, in the manner indicated, is not always satisfac- 



1 The examination of hanging'-drops and the staining of bacteria 

 follows the work which is given in the next chapter. 



