338 



LABELING AND CATALOGUING SLIDES 



[CH. X 



numbers not applicable in a given case may be omitted. With many 

 objects, especially embryos and small animals, the time of fixing 

 and hardening may be months and even years earlier than the time 

 of imbedding. So, too, an object may be sectioned a long time after 

 it was imbedded, and finally the sections may not be mounted at the 

 time they are cut. It would be well in such cases to give the date of 

 fixing under 2, and under 5, 6 and 8 the dates at which the operations, 

 were performed if they differ from the original date and from one 



Jo JO 



Cc (y coven 



t 



Jytrvc. 



FIG. 203. LABEL FOR A MICROSCOPIC PREPARATION. 



The specimen is the myel (spinal cord) of an Amphioxus showing the dorsal 

 and ventral nerve roots, and some nerve cells near the middle. 



G A nerve-cell with glycogen. 



In the label .15 means that the cover-glass is 0.15 mm. in thickness; and s 10 p 

 means that the section is ten microns thick. The date at the bottom shows when 

 the specimen was made. 



another. In brief, the more that is known about a preparation the 

 greater its value. 



527. General formula for cataloguing microscopic preparations: 



1. The general name and source. Thickness of cover-glass and 

 of section. 



2. The number of the preparation and the date of obtaining and 

 fixing the specimen; the name of the preparator. 



3. The special name of the preparation and the common and scien- 

 tific name of the object from which it is derived. Purpose of the 

 preparation. 



4. The age and condition of the object from which the preparation 

 is derived. Condition of rest or activity; fasting or full fed at the 

 time of death. 



5. The chemical treatment, the method of fixing, hardening, 

 dissociating, etc., and the time required. 



