CM. VII.-\ 



LABELING AND CATALOGING. 



171 



uniform the thickness of each may be easily found. The average 

 thickness may be easily determined in any case. 



§290. Labeling Serial Sections. — The label of a slide on which se- 

 rial sections are mounted should contain at least the following : ( 1 ) The 

 number of the series ; (2) The number of the slide in the series (if the 

 series required more than one slide) ; (3) Kind of sections (transections, 

 etc.) and the name of the object from which derived ; (4) The number 

 of the first and last section on the slide ; (5) The total thickness of all 

 the sections on the slide ; (6) The date of the series. 



LABELING, CATALOGING AND STORING MICROSCOPICAL PREPARATIONS. 



§291. Every person possessing a microscopical preparation is inter- 

 ested in its proper management ; but it is especially to the teacher and 

 the investigator that the labeling, cataloging and storing of microscop- 

 ical preparations are of importance. "To the investigator, his speci- 

 mens are the most precious of his possessions, for they contain the facts 

 which he tries to interpret, and they remain the same while his knowl- 

 edge, and hence his power of interpretation, increase. They thus form 

 the basis of further or more correct knowledge ; but in order to be 

 safe guides for the student, teacher, or investigator, it seems to the wri- 

 ter that every preparation should possess two things : viz. , a label and a 

 catalog or history. This catalog should indicate all that is known of a 

 specimen at the time of its preparation, and all of the processes by 

 which it is treated. It is only by the possession of such a complete 

 knowledge of the entire history of a preparation that one is able to 

 judge with certainty of the comparative excellence of methods, and 

 thus to discard or improve those which are defective. The teacher, as 

 well as the investigator, should have this information in an accessible 

 form, so that not only he, but his students can obtain at any time, 

 all necessary information concerning the preparations which serve him 

 as illustrations and them as examples. ' ' 



§ 292. Labeling Ordinary Microscopical Preparations. — The 

 label should possess at least the following information (see § 290 for 

 serial sections) : 



EXAMPLE. 



( 1) The number of the preparations, the 



thickness of the cover-glass and 

 of the sections under it. 



(2) The name and source of the prepara- 



tion. 



(3) The date of the specimen ( 2 of 



catalog.) 



No. 475. 



C. 1 i5_ 

 Sees. 8jil 



Striated Muscle ; transection of the 

 Sartorius of the Cat. 



October 15, 1894. 



