194 SERIAL SECTIONS \_CN. VII 



The name of the embryo and the number of the series ; the number of the 

 slide of that series ; the thickness of the sections, and the number of the first and 

 last section on the slide ; the date. It is also a convenience to have the informa- 

 tion repeated in part on the left end and the number of the first section in each 

 row, as shown in the sample slide of serial sections. (Fig. 211). 



LABELING, CATALOGING AND STORING MICROSCOPICAL PREPARATIONS 



| 307. Every person possessing a microscopical preparation is interested in 

 its proper management ; but it is especially to the teacher and investigator that 

 the labeling, cataloging and storing of microscopical preparations are of import- 

 ance. "To the investigator, his specimens are the most precious of his possessions, 

 for they contain the facts which he tries to interpret, and they remain the same 

 while his knowledge, 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 writer 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 prepara- 

 tion, 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." 



$ 308. Labeling Ordinary Microscopical Preparations. The label should 

 possess at least the following information (see \ 306 for serial sections): 



The No. of the preparation, its name and date and the thickness of the sec- 

 tions and of the cover-glass. 







DATE. 



FIG. 163. Example of a label of an ordinary histologic 

 specimen. (See also Fig. 211 for serial sections}. 



/ / / 



Fig. 163. 



\ 309. Cataloging Preparations. It is believed from personal experience, and 

 from the experience of others, that each preparation (each slide or each series) 

 should be accompanied by a catalog containing at least the information suggested 

 in the following formula. This formula is very flexible, so that the order may be 

 changed, and numbers not applicable in a given case maybe 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 



