MOUNTING 13 



The sections when cut should be removed at once to 

 a watch-glass containing alcohol or water, by means 

 of a camels'-hair brush, or a jet of alcohol or water 

 from a wash-bottle : the useless thicker sections may 

 then be removed, and the thinnest ones selected for 

 observation. 



V. Mounting Objects. Various specimens, whe- 

 ther sections or objects which may be examined whole, 

 require very varied treatment, and the common methods 

 in ordinary use will be described below, and illustrated 

 by experimental exercises (see pp. 25, &c.) ; meanwhile 

 a few practical suggestions will be given which are to 

 be observed in all cases, whatever the special method ol 

 treatment may be. 



1. Study to avoid all unnecessary manipulation oj 

 specimens ; never apply a reagent at haphazard, but only 

 when you have a definite purpose for doing so. 



These rules apply specially to staining reagents, 

 which should only be used when their assistance is 

 actually required : the primary end of the anatomical 

 investigations detailed below is not to prepare a number 

 of objects pleasing to the uneducated eye, but to gain a 

 knowledge of the structure of the plant-body as it is in 

 the living state, and this end may as a rule be best 

 attained by the simplest methods. 



2. See that the glass slide and the cover-glass are 

 perfectly clean and dry, and show a bright polished 

 surface before using them; they should be cleaned 

 immediately before use, and, after cleaning, their 

 surfaces should not be touched with the fingers, nor 

 should the cover-glass be laid flat on the table, but 

 tilted on its edge. 



